I've had this problem before, about a month ago. I get a message saying Company File Won't Backup. I've also have had the additional issue of 'passwords being tampered with...'.
For the Password issue I've followed the instructions but the matter continues to occur.
For the Company File Won't backup, I'm concerned that I will lose my data. I've done a Ctrl-1 of the file with results as follows:

Would you please advise what I should be doing when this matter of the not backing up occurs? continue to post messages in the community?
Many thanks, Lee