Crystal reports 8.5 Invalid Template Error

Please help, I have written a report for a client and when he tries to run it he gets an Invalid Template Error. I run the report against differant data and have no problems. I have spent numerous hours searching the internet for a solution to this error and just can't find one. Any help would be greatly appreciated!

Welcome to the Forums.

Can you tell us some details of your report? DataSource, same report or
different reports, did you create an installation package, etc.