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> Solutions/causes Related To Unrecognizable Database Format, Access 2007    
 
   
bowlesj
post Feb 12 2018, 07:47 AM
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Hi,

Over all the time I have been working with MS-Access (since 1997 I think) I have fairly regularly gotten the message "unrecognizable database format". I have been able to work around it by having a special database that creates date-time stamp backups of my databases and I use this to make a copy probably every 10 to 20 minutes after making many updates if I am doing a lot of work (or every change if it is a tiny bit of work). I zip the file it creates and typically store the last 50 to 200 of them until the pile gets so long and old that there is no way I will need that many. I also copy these files out to another machine and copy the database files out to two others machines. So if I get the "unrecognizable database format" error I go back to the previous ones until I get a good one. After bringing it back in I often do a repair/compress and away I go. I don't loose too much work.

The above was for 32 bit. However now I have one database that gets updated under 64 bit MS-Access on a different machine. When I first started working with this database under 64 bit I could still read it with the 32 bit MS-Access on the other machine. I read it in thinking I might do an update using the 32 bit access or maybe I just wanted to look something up while on that machine. Unfortunately it started getting the "unrecognizable database format" error on the 32 bit ms-access while it could still be read and updated by the 64 bit MS-Access. This has been happening for a few months.

The problem I describe was only an annoyance. However now I am getting concerned. I installed the 64-bit ms-access program I think in November just past or whatever. The Hard drive on my 64 bit ms-access machine just after that started showing signs that it was going to completely fail soon (4.5 years of hard drive use). I bought a new hard drive and I am reinstalling Win 7 from the CD rom I bought and all my software. I have to go back to download the MS-access 64 bit from the Microsoft store website later today. I am a bit worried that it may not read this 64 bit database (it should be okay but that error should not happen and it does happen so one can not be too sure). The worry has got me thinking "Surely there is a better way to deal with this than just backing up like crazy. Maybe I should finally break down and ask people who knows a lot more than I do about this and Access in general.". Does anyone have any better ways to deal with this regularly occurring problem. I have run into this error at least 100 times.

I just tried starting MS-access 32 bit all by itself then doing a repair/compact without the database loaded and it gives the same error.

Thanks,
John
This post has been edited by bowlesj: Feb 12 2018, 08:08 AM
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GroverParkGeorge
post Feb 12 2018, 08:07 AM
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It is not surprising at all that changes to the accdb under a different version of Access would render it unrecognizable under a different version. Typically we see this when an accdb is opened under a later version and modified, adding features not available under an earlier version. Moreover, unless I am remembering badly, 64 Office was introduced in the 2010 version, so I would have to assume that you are, indeed, using 64 bit Access 2010 or later here. And that's the problem, if it's the case.

Am I interpreting this wrong? Do you have Access 2007 in both 32 bit and 64 bit versions? I'm going to go do a quick Bingoogle to verify my memory as well.

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bowlesj
post Feb 12 2018, 08:11 AM
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Hi George, my 64 bit access is 2016. the 32 bit access is 2007. So far the error on this specific database has not occurred under the 2016 64 bit access. However the 100+ prior errors have always been under the same version I created the database under. I have only ever used access 97 and access 2007 and now access 2016 for a few months. If I was to total the number of changes to a database I have made since 1997 it is probably a million plus. So in a way 100+ of these errors is not that bad statistically which is probably why I just keep up my old habitual method of handling it.

I am thinking someone out there may not back up like I do and may have thought to themselves a C program should be written to analyse and fix or extract out to to a text file or something. I am not even close to being capable of this. However I think maybe some are (people like the people who wrote speed ferret). I am guessing it would be easier to write than speed ferret was. It is just a thought. If it exists I might buy it. But then again maybe my method of backups every few minutes is easier come to think of it. Maybe others do what I do and just accept it and never report how often this error actually happens.
This post has been edited by bowlesj: Feb 12 2018, 08:28 AM
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GroverParkGeorge
post Feb 12 2018, 08:26 AM
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I see. Well, the current problem is that later versions of Access can, and usually do, make changes to the accdb that render it unrecognizable to earlier versions.

You opened it and, I assume, made changes to it with 64 bit Access, but in a later version. It will not be usable under Access 2007 now.

The standard approach is to either maintain one version of the Access for all users, or maintain separate versions of the accdb for the two (or more) versions of Access in use.

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bowlesj
post Feb 12 2018, 08:30 AM
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Okay, thanks George. You helped me realize that my Idea to only change the other 32 bit databases using Access 2007 32 bit is a good one. None of them need to run under 64 bit but I do read them under 64 bit at times to save having to turn the other machine on and waste power.
This post has been edited by bowlesj: Feb 12 2018, 09:05 AM
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GroverParkGeorge
post Feb 12 2018, 09:48 AM
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That sounds reasonable. But remember, the BIG issue is NOT 32 bit vs 64 bit. The BIG is 2007 vs 2010 or 2016. Even if you use 32 bit versions of Access 2016, you'll probably render the accdb unrecognizable to Access 2007.

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bowlesj
post Feb 12 2018, 01:49 PM
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Actually I am forgetful. After my info paragraph I have a question.

Info:
I just realized I have been updating two other databases using access 2016 which I must keep running under access 2007. They are my (music guitar technical practice database) and (my music songs database). If you are curious I do a lot of guitar practicing because of the jazz jamming group I run with the help of the the website I programmed. I am retired and it keeps me busy and my mind working :-) Luckily these databases are still being read by 2007 access. This is probably because these two music databases are much older and programming changes were not that significant. The market trading database that will not longer run under 2007 is the one that can only run under MS-Access 64 bit (2016). I got lucky. The market trading database's not working under 2007 provided me with a heads (along with your info) as to the danger involved. So I have left myself a reminder in my reminders database to never make programming changes using access 2016 to the databases I need to keep running under access 2007.

Question:
However (due to the location of the two computers in my limited office/desk space) it is much more convenient for me to do data updates to both of the song databases on the computer running 2016. Does (doing data updates only) using access 2016 put these song databases at risk of not running on access 2007?

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bowlesj
post Feb 12 2018, 06:08 PM
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In a way the subject has been lost. My question should be rephrased.

Does (doing only date updates to a database with access-2016) put them at (greater risk of not being able to be read by access-2007) than the regular risk that is created from only using this database with 2007. The regular risk in my experience being about 100 unrecognizable database format errors over 20 years of use using both access-97 and access-2007 (but not both at the same time).

My guess is there has been no research done to properly answer this question and now I am thinking that backing up like crazy and returning the backups after this corruption is the only solution. Since returning the last good backup does work I have to assume that something unusual and random goes wrong during the update or during the write to make the database unreadable the next time around.
This post has been edited by bowlesj: Feb 12 2018, 06:10 PM
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GroverParkGeorge
post Feb 12 2018, 09:54 PM
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I would NOT do anything with an accdb in a later version of Access(i.e. 2016) if I know that others will have to use it under an earlier version of Access(e.g. 2007).

You may get away with it. It might cause problems just to open it. I avoid it by keeping four Virtual Machines in addition to my primary development machine, one each for Office 2003, 2007, 2010 and 2013. I only run Office 2016 on the main computer.

It's a hassle, sometimes to remember that I have to honor that schema in all cases, but the payback is not having to recreate an accdb that got converted because I opened it in the wrong version.

This probably falls under the category of good practices we hear about from time to time.

I do realize I have a certain luxury in being in a position, as a consultant, to have an incentive to invest in multiple versions of software.

Of course, you have 20 years of your own experience to guide you, so whatever you think you need to do is probably for the best.

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DanielPineault
post Feb 13 2018, 06:19 AM
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My experience has been just opening a database in 2016 has made the database unusable in earlier versions. So the golden rule of always working with the oldest version of Access that will be used to run the database critical for any and all development work and equally important that if your users be given their own independent copy of the Front-End.

It can be a hassle, but it is what needs to be done to avoid such headaches.



--------------------
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Free MS Access Code, Tips, Tricks and Samples: http://www.devhut.net

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* A user interface is like a joke, if you have to explain it, it's not that good! -- Martin LeBlanc


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bowlesj
post Feb 13 2018, 08:44 AM
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Thanks guys, your comments have me more on alert. After (reading George's comment) and (having an unusually good sleep compared to normal) I came up with an idea which often happens after/during my night of sleep. After reading Daniel's comment I know I definitely have to do what I describe below daily.

Since I have not had Daniel's experience (yet at least after 2 or 3 months of fairly regular use of the songs databases under access-2016) I decided to do a check. I just did a compact and repair of these two databases under access-2007. They both had a successful compact and repair. I backed them up with the date and time stamp plus the comment "Readable_C_And_R". This backup gets zipped and copied to all 3 of my machines (it gets included in an archive on another drive as well). I am very cautious regarding backups. Regarding the test I did it for two reasons (to test for two problems it use to uncover). Just being able to open it proves it does not have the "unrecognizable database" error. It also tests for another error I use to get under access-97 which is where some of the forms get corrupt and I would have to rebuild them using a procedure I still have documented in my reminder system database. I also did this test and backup to the reminder system database just in case since I regularly open it under access-2016 even though I never update it there (as implied by this sentence it too passed the test). Of note I also run the date-time-stamp-with-comment backup under access-2016. Having realized this I applied the same test and backup here (I have a special backup program to apply a date and time stamp to my main backup program). To give you a visual I put the backup name in quotes below.
QUOTE
20180213_0829_BackupWithDateTimeStamp_Readable_C_and_R.zip


So I created this reminder in my reminder database with an up front comment to keep me in the habit of doing the above described check at least daily until I have a problem.
QUOTE
Daily or more. On the XP machine do a compact and repair of the songs database and the guitar practice database then backup labled "Readable_C_and_R"


I just realized I have to refine this reminder to include 5 databases.
QUOTE
Daily or more. On the XP machine do a compact and repair of 5 databases then back them up "Readable_C_and_R" (practice, songs, URLs, calendar, backup)


If I have a problem I will have to figure out how to rework my office to allow me to practice guitar during the day such that these guitar practice related databses run on the machine using access-2007 while at the same time I am running the market trading database under access-2016 on the other machine (it regularly gives me notice I have to inspect a chart for possible followup). I hope it does not happens since it will be a bit cramped and probably require a new office chair that swivels very well :-) Also if this ever happens hopefully I don't have to jump over the equipment to get to the door...lol. At least if it happens I will only have lost a days work and I ams sure I can continue on.

Either way I will keep you posted.

Thanks,
John

P.S. This is the only forum I know of that cuts off updates very quickly. I often go back and reread posts and notice errors I would like to fix but I can't on this forum and late readers may be confused when they need not be. So I just used a TTS (text to speech) reader software to help ensure my post conveys the message I want and has minimal spelling and typos. I do this on my website often and during emails to my jazz jam group. You might want to recommend this to people who post regularly. Hearing the post helps find errors. As an example I just changed "my TTS" to "A TTS" since "My" would imply I wrote the software when I did not. I just watched a video by a professional editor and it seems they use TTS software often for this same purpose. I stumbled on it while trying to figure out how to get the Microsoft Mary or Zira voices to run under Windows 7.
This post has been edited by bowlesj: Feb 13 2018, 09:04 AM
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bowlesj
post Feb 13 2018, 10:06 AM
Post#12



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One interesting after thought. The difference between Daniel's experience and my experience begs the question why? This leads back to the original topic. Is there a better way to deal with this problem of the unrecognizable database error other than just returning a backup of a working database. I guess it would take a combo access programming expert and c programming expert to come up with something that could answer the why question and maybe develop a fix (again remembering it can happen even when not crossing versions of access).

I am not an expert in either area and have zero C programming experience. I am very much a generalist with my biggest experience in these areas descending: COBOL, UNIX shell scripting, ms-access, multicharts power language, PHP, javascript, trade station language, and tiny bits of other languages (assembler, jquery, machine language, RPG-II, etc). Not only that I have spent a lot of time in areas away from programming too. I was a guitar instructor up until age 26 when I went into programming then later got back to teaching guitar at age 56. I also jumped the programming ship all together at age 47 to trade markets for 13 years while doing a lot of ms-access programming and multicharts programming to help with this.
This post has been edited by bowlesj: Feb 13 2018, 10:23 AM
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GroverParkGeorge
post Feb 13 2018, 11:07 AM
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Please just follow a couple of simple rules and you should be fine.

If you plan to work with an accdb in 2007, never open it in 2016 (or 2010, 0r 2013 either). Always open it with the version you intend to use it with, only.

If you need to work with an accdb in a later version, make a backup and use that backup with the later version, not the original, unadulterated, 2007 accdb.

Continued Success with your project.

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bowlesj
post Feb 13 2018, 08:21 PM
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Okay, thanks George.
This post has been edited by bowlesj: Feb 13 2018, 08:23 PM
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