I have a class library app that interfaces with an ERP to print the report. I understand this is a compatibility issue, but here is the conundrum: The ERP only supports Crystal Reports Runtime SP20 but I can only find Crystal Reports for Visual studios SP27. I can't upgrade the runtime because it breaks all of the reports/forms in the ERP. I have read that you can add code to the app.config to make old apps work with new runtime, but I have the opposite problem i.e. new apps on old runtime. Is there any way to bridge the gap? Getting an older version of crystal reports for visual studio could work, but I can't find it.