getting error when i open project in mendix pro 9.1.1

i am working on mendix pro 8.18.2 and i want to open this project mendix pro 9.1.1 . when i run this project in  mendix pro 9.1.1 then i am getting this error. Buildfile: C:\Users\Rahul\Documents\Mendix\Inspection_Mobile_App-main\deployment\build_core.xml clean:    [delete] Deleting directory C:\Users\Rahul\Documents\Mendix\Inspection_Mobile_App-main\deployment\model BUILD FAILED C:\Users\Rahul\Documents\Mendix\Inspection_Mobile_App-main\deployment\build_core.xml:7: Unable to delete file C:\Users\Rahul\Documents\Mendix\Inspection_Mobile_App-main\deployment\model\bundles\project.jar Total time: 0 seconds   can anybody suggest me the solution of this error.
1 answers

Have you followed the steps listed here in the documentation about moving from Mx8 to Mx9? I don't know if it will solve your issue, but if you haven't followed them yet it's a good idea anyway.

It may be worth trying to upgrade to 9.0 first and then upgrading further as well, to see if that changes things.