That seems strange. Did you put it at the beginning of Init? Nothing should be loaded before Init, but Init will cause other things to be loaded.
There could be things in the old stdlib that are incompatible with the new exe. You could run CheckLibrary(“stdlib”) to make sure everything compiles. Or CheckLibraries() to check all the libraries in use. Do the stdlib tests all pass?
I would recommend upgrading to the latest stdlib if you have time. There should not be too many incompatibilities, and there are lots of fixes and improvements.