Sharing Violations

Not really unfortunately, but it sounds like an OSX permissions issue.  The fact it only happens in a network share would support that - I presume that in your case, alternatives that work are files in users home directories.

Have a think about the commonality of users who create the Excel files that work/don't work vs other apps that work.  Are there lots of users involved, some who can, some who can't?  If you open a file that you can't save does it tell you it is read-only?  What happens if you open the Get Info pane on a file and click on locked then open it - does Excel report it is read only?  What is the difference if you open a file and then get someone else to open that same file - does it flag an issue for that second person?  

Can you set up a test using that info plus the info I give above?  As a thought, create a folder on that share, put files that work and don't work in it, set up a group and add users to it then assign permissions to the group and folder and see what happens.

Those are rhetorical questions to give you some more pointers in tracking it down.  I'm trying to think what could be done in an application that would cause it to NOT flag up as read only but then prevent saving and I can only think of permissions that aren't immediately transparent.  What I found is that looking at permissions via Get Info doesn't help: in my case, the file had read & write permission for myself, my wife, everyone, staff, wheel and so on.  Didn't matter, it didn't work: I had to set up the group and set the permissions as I note above.  Something that I couldn't narrow down was higher in the permissions checking sequence that was preventing us as users from updating it, only the Owner was allowed to do so.  I think Catalina has really cracked down on security which might be why it hasn't been a problem previously.

However, having said that, others like yourself, have said it only affects Excel, worked in previous versions etc so we could be dealing with different problems, I really don't know, sorry.

In my case the problem occurs only with Excel, and only with some files...with others theres is no problem at all. Also, it only happens when opening files in our network share. Any tips? 

We are  in the same position, antonioj.f. It's only an issue with Excel (although I work primarily in this app so issue has had more opportunity to occur); only occurs when saving on network shares (on both our Windows file-servers, one remotely-located using SMB, one local spoofing AFP); and only occurs with some files and with no apparent consistency or cause (doesn't seem to be influenced by file size, file type (.xls/.xlsx/.xlsm), or whether a new or re-opened file).

Having tried everything suggested in this thread, the only successful solution for us has been to roll back to v. 16.29 of Office (and disable auto update!). I have not once encountered the issue since running the older version. Until MS acknowledge the issue and announce a fix I'll be sticking with 16.29.

@Lordsaveme thank you for your suggestions, but i have no time for extensive testing...if i can roll back to 16.29 i will prefer doing that.

@srd77 how did you roll back?

Figured out how to roll back to 16.29, and it does work! I also will be sticking with it until someone reports there are no more problems!

Reverting back to 16.29 had been working for me for the past few months but last week even that failed (Sharing violation alert , followed by save as *.MACTF, ...). So I've updated to the latest version of Excel (16.33, 20011301) which still has the problem.

When I first upgraded to 16.33 I did not have the option to grant Full Disk Access, or even Network Access but a few days ago that option appeared, although there’s still no option available to grant Network Access nor to manually add it (i.e., the “+” icon is grayed out). After granting Full Disk Access to excel the problem went away for about a day but now has returned.

This error only occurs when attempting to save to my Synology NAS and only Excel files have the problem. NO problem saving too the NAS with any other programs such as Adobe Lightroom or even Word. Some of the Excel files are edited by one other user, many just by me. My current workaround is to open Excel files from the NAS, make my changes, save as to a local folder, then use finder to copy the file back onto the NAS.

I believe this began before upgrading to macOS Catalina, with no change when I finally did upgrade to Catalina.

I’m headed out of town and until I return will not be able to add to look into the OSX solution LordSaveMe has proposed (the NAS is on a local network). However er, it sure seems to me to be an Excel problem and wish Microsoft would fix this problem! Especially since jacsdad was able to get support to duplicate the problem and they promised a fix would be made several months ago.

Thanks

-Ray