I developed a very simple Db for a client to replace an older app. I used my PC, running Win 10 PRO and Access 2016 full version. The same app runs OK on the clients Win 10 PRO machine with Access 2016 runtime EXCEPT when running any report, I get a fatal exception and the app has to close. I tried 32b and 64b 2013, 2016 versions, all the same result on the client's machine. Any ideas? I don't want to load a full version on the client machine, set the code, try it then uninstall it - just yet. Not if there is a "head slapping" DOH! I am missing.