Exe with dll build fails

I am using PB 12.6 working with a fairly large (~24 pbls and quite a few objects in each) PB application that has always been built as an exe with pbds.  I am new to the application and trying to build full, machine code, speed, as an exe with dlls instead since that is what I have done with "my" PB applications since 1997.  But the deploy crashes during the process.  I reviewed the log file but it only says CODEGEN compilation error and the log file says "syntax error; probable cause: missing ';'.  All objects regenerate fine and the PBD build deploys fine.  Hopefully I have provided enough info.  Any help appreciated.  BTW, if anybody knows of any serious or gotcha bugs going from PB 10 to 12.6 that would be helpful too.