Here's a check.
You get this error, because either the file name , the path is invalid, or CR cannot access the file.
If the path and file name are ok, you need to make sure the Network Service has read / write to the Temp folder (usually C:\windows\Temp ).
If the problem is still not resolved, your Temp folder may be full and CR will not clear the garbage.
If so, you need to make sure that you properly repair the report object and call the GC to clean it.
Several times, CR behaves unpredictably. I learned it with difficulty, but even if you call the ReportDocument object, followed by GC.Collect() , and the .rpt files in the Temp folder are not cleared. And there is no limit. .rpt files in the Temp folder, after which CR stops performing further report requests.
This happens strangely when you declare your ReportDocument object as a function or event handler. But if you declare your ReportDocument in a global global scope , then crystal reports will happily clean up temporary .rpt files when you call Dispose !!
I hope this gives you some insight into fixing the problem.
source share