When Excel couldn't save a file, 3E0CF950.MACTF was created, but where and by which program?

Copper Contributor


Currently running:

  • Mac OS 10.14.6
  • Excel with Office for Mac 2021
  • Manual copies to iCloud.


Also running with Parallels Desktop:

  • Windows 10
  • Excel with Office 365 for Windows
  • Autosave copies to OneDrive.




I would appreciate some assistance with an unusual problem involving Excel for Mac 2021 and possibly with Mac OS X, Excel for Windows 365, iCloud, and OneDrive. I generally create, edit, and save my workbooks using Excel for Mac and Excel for Windows 365 on the same file and never had any problem.


After making edits to a workbook, I tried to save the file in Excel for Mac 2021. A message appeared saying that it could not save it due to some sharing violation. It did not specify the message's source, nor a directory path or the enclosing directory name to help locate the file. Instead, it instructed me to close the workbook without saving it and to access a file named 3E0CF950.MACTF, rename it and save it as a regular Excel file.


Microsoft technical support instructed me to search at:


But the was no AutoRecovery directory. I also searched unsuccessfully on iCloud Drive and OneDrive, where I have autosave enabled when I edit my workbooks in Windows 10. I have also searched for it using Spotlight and the FIND command of the Finder with hidden files made visible. Nada.


Although Microsoft tech support thinks that the file does not exist, however, I think it's unlikely that I would get a message so detailed to include the filename if none was created.


A similar issue happened about a year ago before I had Excel for Windows installed. I was never able to find a resolution for it. Has anyone else experienced this?


Before giving up, would anyone happen to know:

  • Other locations to search on my Mac?
  • A safe command line for Terminal to search more thoroughly? 
  • If Excel would create temp files with the ".MACTF" extension, or could this be a product of the Mac OS, iCloud or the OneDrive to which I enable autosave when I edit my Excel workbooks in WIndows?
  • Whether the file name "3E0CF950.MACTF" ïs a random name, or is it a generic file name specific to my issue, and if so, what does it mean?
  • If it's normal for Excel for Mac 2021 to lack an AuitoRecovery folder?

Your kind assistance would be much appreciated. Please advise.

7 Replies

Hello@LChoiSF ,


I, unfortunately, also just faced this same issue. I was working on an excel file and went to see but was told there was and "error saving and a temporary file 'EA8DAA70.MACTF' was made. Rename it and open with excel" couldn't find it anywhere. I went to terminal and wrote: "open $TMPDIR" this was sending me to the temporary files but still found nothing. I saw a post from the Microsoft team saying they don't know about .MACTF and to contact Apple support. Apple support just went through the same things I did and nothing was found.

If you had any luck, or if anyone else knows what to do let me know.




@LChoiSFencountered the same problem, has a solution been found?

Only time I have seen behavior like this it was a disk permissions issue on a MAC using an external Drive, and I think the MACTF file is a MAC OS thing, not an excel thing.

If we made a new excel, saved it locally and moved it to the external drive it was fine. You could read it, open and edit, but trying to save it would cause the error again. It was because Excel didn't have full access to the secondary drive so the mac would kill it on save attempt, and throw errors.

We had to add the Excel application (and the Drive's client software) to Full Disk Access in System Preferences - Security & Privacy.

@Apeterik dealing with same issue. Started with Apple Support, they're telling me "ask Microsoft." Classic finger-pointing! Not me! Not me!

@LChoiSF I have exactly the same problem. The name for the archive is 

683FB360.MACTF and it's impossible to find it anywhere.



Have a quick research and seems related to permission issue