As there are no strict rules on DLL naming, it is possible that an ESL supplied DLL has the same name as a DLL supplied by a third party. The DLL that supplies Message Box support, i.e. MESSAGE.DLL, is a prime example. Whilst it is possible to change the library name defined in each external subroutine and function prototype, then recompile, there is a far more convenient approach. You merely have to change the MAPENTRY statement in ESL configuration file. For example, if you find 2 versions of MESSAGE.DLL on a machine that is behaving strangely, rename the DLL in the ESL directory to a new unique name, say ESLMSG.DLL. Edit the ESL Configuration File (EslConfig.ini) using a suitable text editor (e.g. Notepad) and change the MAPENTRY for MESSAGE, so it is now:

MAPENTRY=MESSAGE ESLMSG