Error is

The following error occurred when attempting to connect.  Formula 'PrintGLVariable' uses the following unsupported functions: StoreStringVar

Formula 'PrintGLDistribution' in subreport 'CheckStub1' uses the following unsupported functions: FetchStringVar

Kinda explains it all right there. You have to go into subreport CheckStub1 and in the formula PrintGLVariable you have to delete "FetchStringVar" even if it is probably noted out.

That seems to have fixed it. The formula did have "FetchStringVar", but it was noted out and was updated with the new formula in version 2013. I wonder why having "FetchStringVar" noted out didn't cause any issues with previous versions of Sage.

The new version checks for the bad formulas because without this customized check forms would cause intermittent crashes during check printing, with no explanation.

Unfortunately, the formula validation is not intelligent enough to sense if the bad formula has been commented out, which was our standard practice... so we'll get false errors during customer upgrades to v2016 now.

Thank you for the explanation! "False errors" that cause the checks not to work at all. This is going to make upgrades very time consuming especially when the client has several company codes and check forms. I have an upgrade next week where there are 58 different company codes and 5 or 6 different check formats, but the client can't identify which companies have the same check format so the time figuring that out and copying the check form vs removing the commented out part of the formula on 58 different check forms is probably about the same.