Are your backup files directed to the .SAJ folder? if so the folder will get so big it cannot handle the volume. Remove all the .CAB files from the folder and save them in a different folder. Be sure to redirect the backup files to the new folder. This may help your problem.

No .cab files in the .saj folder. I have too many files repeated. : performance_schema - 5 files; mysql - 5 files etc...ib_logfile0xxx - 10 different files, all with same dates.

Just another suggestion - it looks like you might have installed five different Sage 50 files all in the same folder and the process did not overwrite the older one. If you are using the Accountant's Edition, which is most likely for this to happen, when installing I always add the year to the location for the files. By doing this you still have access to be able to run the older editions for a client.

Maybe???

I only have one company so I don't know why I would have 5 different files... this is very strange.

These are not company files, they are program files. I would still uninstall Sage 50 until all of these are gone and start fresh.

I will try that... but it scares me I don't want to lose everything ...

Uninstalling the program will not affect your data. Be sure your data file is backed up to a new folder away from the current location for backups and program files.

That's the thing, I cannot back up at all ! It does not even give me the option to change the folder ! I only get the message saying that it's impossible to back up because the file is more than 2 go

What is your exact path to your data? and to the folder you showed in an earlier post?

I want to feel comfortable that your data is safe. 

Getting into specifics here.

I found the way to correct this !!! I saved my file under a new name, adding 2021 at the end so I could recognize it and therefore a new .SAJ was created. I then erased all double files of each type. Then restarted my computer and bingo... No more problem ! I did a backup and it's all good now.

By reading your answers, I tried a few things and finally got the problem solved. Thank you so much for your time !!!!

I found the way to correct this !!! I saved my file under a new name, adding 2021 at the end so I could recognize it and therefore a new .SAJ was created. I then erased all double files of each type. Then restarted my computer and bingo... No more problem ! I did a backup and it's all good now.

By reading your answers, I tried a few things and finally got the problem solved. Thank you so much for your time !!!!

Happy to have been able to help.

Have a great week