When including the FMU for a rel-time application, i got this error when compiling die app

Making Makefile "CfgDeskInterface.mk"
In file included from f2c.h:162:0
                 from iparmq.c:13:
iparmq.c: In function 'iparmq_':
iparmq.c:24:12: error: expected declaration specifiers or '...' before numeric constant
     double log(doublereal):
            ^
Compiling failed  "C:\Users\User1\Documents\dSPACE\ConfigurationDesk\6.2\FMU_import_test\TopologyTest\Components\Simple_Topology\sources\external_solvers\iparmq.c"
Making Makefile "CfgDeskInterface.mk" failed

i know its not directly OM related theme, but i've try to google it, but have not really understand whats the error means. thank you in advance