A .crc file is a log showing circular references in an assembly. A circular reference can occur, for example, if you model in context of an assembly and then use the feature you created to place the model. As such, the model cannot be solved. Regards
I have found that most circular reference problems can be solved by re-constraining the referenced model or sub-assembly to the main assembly datums, then removing any constraints referring to models/subassemblies indicated in the .crc file.