Incorrect vpp revision when download server revision 51,30

Hi guys,
when i try to commit my changes an error occur :
incorrect vpp revision when download server revision 51,30.

I know the reason for this problem, but I dont know how to solve it.
Here is the whole story:
The current version of the project is 51 but after revision 30, we change the repository address and unfortunately we forgot to update that address for one of our users and he continues working on the revision 30 .during the time that other users were working and committing their works, that user continue working on his local copy of revision 30 and he did not update or commit the project any more. Now after a few revision(30 to 51), he want to commit his changes but he cant commit on the new repository location.
i changed the setting of repositories and remove the old location but now i cant commit the changes to new repository location because of the error i said.
please help me solve this problem.
thank you in advance

Hi,

Can you checkout revision 30 in new workspace, then replace vpp by his local copy and commit?