update broken

I had an old version and updated, there was no way to update so I installed the com_osmembership.zip right over it, got this message:An error has occurred.

0 Call to undefined method OSMembershipHelper::executeSqlFile()

Then I did it again, and it worked.  

See portal.crediblock.com  

Hello

The method is there, so I don't know why that error happens. Maybe it is something special on server (for example cache which could cache the old php code....)

At least re-installation worked, so it could be used as a solution

Tuan