Yes

>>>This is not my first app running on the client location. My other apps are .Net 3.5. No problems putting our CR reports in those apps.
>>>This app I did in VS2010 using 4.0. Of course, CR was not included, which led me down this long, horrible road. I have been spending all week getting CR to work in my .Net 4.0 app.
>>>
>>>On the client machine where this is dying, you're saying that on the same machine, someone has been able to run CR reports from .NET 3.5?
>>>
>>>I'll keep thinking....maybe someone else here has an idea....but something tells me this is something with the environment. (That would possibly explain the error message not being helpful)
>>
>>Yes, that is correct. I have other 3.5 apps running CR reports.
>
>Did you install the CR redistributable for VS2010 on the client's machine? There's a boostrapper idea here:
>http://www.sourcehints.com/articles/creating-crystal-report-bootstrapper-for-vs2010.html
>
>Otherwise, did you install this redististributable on the client's machine? http://www.businessobjects.com/jump/xi/crvs2010/us2_default.asp
>
>(Check for the 64-bit if you need that for your clients - I didn't see you mention 32 or 64 specifically)