Thank you for your post.
I'm assuming you are opening another FileMaker Pro file, because FileMaker Pro will not allow you to open a file automatically.
Once you open your file, under File -> Define -> External Data Sources, you probably have the old file listed there. Remove it, and you should be fine.
It sounds as if there is an opening script running.
Check File > File Options… to see if a script runs when opening the file.
If yes, check the script and see what file it is trying to create.
YES! It is performing at Auto Backup, which is probably the default, right? I unchecked the box and launched it again and the error message went away.
Question is should it Auto Backup when I launch?
No it is not a standard action to perform a backup when a file opens. The default is that no script runs when the file opens.
What you need to do now is to review the Auto Backup script and see why it is failing. There may be a number of reasons and I can only guess without seeing the script.
I think I found the culprit:Scripts>ScriptMaker>Auto BackupThe file creating the error was in the big field on the lower right. I highlighted it and deleted it. That seemed to solve the problem.