You can specify the type of data structures used by the HLLAPI DLL supplied with a particular emulator by using the variable HllapiDLLType. Whilst the correct IBM EHLLAPI standard uses 32bit structures, certain emulator packages use the older 16bit structures which were used within the original HLLAPI standard when 16bit addresses were used by Windows. The following is the default setting:

HllapiDLLType=32 

You will need to review the emulator package documentation to determine, whether 32 or 16 bit structures are used. If the documentation is not available, use the ESL Development tool "ESLFields" with the troubleshooting option, to trial the different setting.