Go into the project folder and rename
[projectname].Xstage to [projectname].Xstage_backup
[projectname].aux to [projectname].aux.backup
Then rename the actual last backup files:
[projectname].Xstage with the “tilde” character to [projectname].Xstage
[projectname].aux with the “tilde” character to [projectname].aux
The “tilde” character which I can’t type here looks like a wave.