LibPTP installation failure

Hello, trying to compile LibPTP on Omnet 4.6.1 fails with the following error:

10:32:53 **** Incremental Build of configuration gcc-debug for project libPTP ****
make MODE=debug CONFIGNAME=gcc-debug all
cd src && make
make[1]: Entering directory '/home/supertjhok/libPTP/src'
Software/PTP_Stack/PTP_Stack.cc
In file included from Software/PTP_Stack/AppServices/Announce/AppAnnounce.h:31,
from Software/PTP_Stack/Port/PTP_Port.h:33,
from Software/PTP_Stack/PTP_Stack.cc:33:
Software/PTP_Stack/AppServices/PortService.h:55:42: error: could not convert ‘cBasicService::BasicServiceEvent::NEXT_FREE_ENTRY’ from ‘cBasicService::BasicServiceEvent’ to ‘int’
55 | TIMEOUT = BasicServiceEvent::NEXT_FREE_ENTRY,
| ^~~~~~~~~~~~~~~
| |
| cBasicService::BasicServiceEvent
make[1]: Leaving directory '/home/supertjhok/libPTP/src'
make[1]: *** [Makefile:515: ../out/gcc-debug/src/Software/PTP_Stack/PTP_Stack.o] Error 1

Any suggestions on how to fix the error?