Don’t know if it would make any difference, but have you tried opening it both from the folder where it is, as well as from within Finale. You could also export it as XML, and import it. You would lose some formatting, but it may save the file.

Thanks, Mike,

  I don't know if that would work, but I'll give it a try.

  I'm having a similar issue on a different file:

Any ideas?

Do you have a backup or temp file that you can try?

No external drives.  Saved some to the cloud, but they were all older versions.  This has been happening a lot.  Somebody's out there moving pointers?  Huh?

This is not acceptable. Finale is not opening my old .mus files. I have thousands of them, and now with the latest OS on Mac the old Finale software versions no longer work, which was the only way to open them (ie open with old Finale version and save as musx file). Time to fix this guys. It's not good.

Andrew Partington,

Please specify the steps you've already taken (to solve the problem), so that we can rule out things.

Have you e. g.

- tried changing the file name extension from .mus to .musx?

Has any progress been made at all on this?  I'm a teacher, and the final project for my class just had this happen.  This was SO much work, and there are no back ups.  Didn't know that was a thing. 

>Didn't know that was a thing. <

Actually, it isn’t a thing. Finale opens old files. We need to know a lot more about your situation. Start by reading this:

https://makemusic.zendesk.com/hc/en-us/community/posts/215729367-General-Discussion-House-Rules 

I opened a file, and then my computer ran out of batteries while working on it.   I tried to open it up again later and I get the same message other people are getting where it says "Cannot set position in the C:\Users\Isaac\Desktop\Hungarain Dance Orchestra.mus

An attempt was made to move the file pointer before the beginning of the file."

I can't seem to open it, and unfortunately I have no back ups.  Just wish i learned this lesson on a less important file.

Have you sent this to MM Support? If not, use the Submit a Request link at the top of the page. Even if the file is corrupted, it may be possible to recover some of it. You still haven't told us the particulars including the version of Finale that created the file. 2012 defaults to .musx, not .mus.

I had the exact same issue happen to me which happened to Isaac Gish. Any update on solving this issue to fix the file; or should I assume the file has become corrupted and start over (which will really suck). I've already sent a report to MakeMusic; and they can't/won't help me because Finale 2012 is considered a legacy program.

>> Any update on solving this issue to fix the file

Keep backups. One can append a datestamp (yymmdd) to them to keep them straight.

Sorry to be brutal, but things happen.

>I had the exact same issue happen to me which happened to Isaac Gish.<

Have you tried to open it in 27? If not, try the demo and see if you can. 2012 is no longer supported but 27 is.

Otherwise, my advice is the same as Adrian's. Files can get corrupted—especially if active during an unexpected power loss or other crash. Regular backups are your only insurance—you might lose some recent work on a file but you're unlikely to lose all of it.

Apple's Time Machine backs up hourly but there are Windows apps that can do this also. If you have a paper or .pdf copy, scanning apps can restore all or part of a file, too.

I ended up updating to 27; and unfortunately, that did not fix the issue either. Oh well, lesson learned the hard way.

Well, I'm certainly no expert, but, when I updated from 2012 a few years ago to whatever I have now, this problem was fixed.  A simple search from the File Explorer was sufficient.  But like the guys say, a lot more info is needed.

Don't forget things like cloud storage.

This is going to sound silly but… Try making a copy of the file then change the name of the file appending an “x” to the end of the file identification suffix. Eg rename “filename.mus” to “filename.musx” then try opening that one. This has worked for me before

Oh if file is on iCloud sometimes you have to download the files first to make them open. Sometimes this takes a while and sometimes it’s hard to tell if the file has downloaded yet or not. 
This is all more obscure under Big Sur actually. 

>Don't forget things like cloud storage.<

>Oh if file is on iCloud sometimes you have to download the files first to make them open. Sometimes this takes a while and sometimes it’s hard to tell if the file has downloaded yet or not. 
This is all more obscure under Big Sur actually. <

Marketing giveth and the details taketh. Although iCloud, Dropbox and other cloud services make it seem like you can just upload a file and be able to work anywhere, that is often not the case. For one thing, neither are client/server environments like GoogleDocs and NFS (Network File Sharing), Citrix etc. Although it's ok for my clients and I to collaborate on a Word doc in the cloud, if something happens, data might be lost—but it's a Word doc and my client is working on a copy sync'd to the one in my hard drive so there's very little chance. We ask DAWs and Notation to perform tasks in real time — internet for most of us isn't that good yet. It's fine for word processing, database and spread sheet apps as long as you're aware of the risks.

Dropbox wants to sync all your files "to save space" and remove the ones you seldom use. Oh hell no! if you use Notation apps or DAWs. Read the fine print—your most used files remain on your computer and DP removes the seldom used files. There are good reasons for that. A hiccup in your internet can corrupt a file if you're working on it at the time and its only location is the cloud—same as a sudden crash on your PC or Mac. Fortunately, you can opt out of that and should. Only the files in the Dropbox folders on my Mac are sync'd to DB and I work on the local copies only (as in the example above). Dropbox marketing wants you to check that Save space... box so watch out. I'm not saying don't use it—it's important to my work.

>This is going to sound silly but… Try making a copy of the file then change the name of the file appending an “x” to the end of the file identification suffix. Eg rename “filename.mus” to “filename.musx” then try opening that one. This has worked for me before<

It has worked for others, too.