urgent 911:-50050 error

why does this error happen? who can tell me? I can run a view proint pro report in program. but can't run it in program after I upgrate the report software to a new version. I can run the report software and open the report file. but I can't run it in the original program. happen the following error: -50050 error error text is " The file could not be opened" " The message is generated by the ixFile constructor if it cannot open the specified file" So why?