I get no error at compile time but I've tried again and I don't get the error anymore.
It's not clear why, given that I tried several combinations, but the error was on some commented codes.
In the topic I copied the code where all conversionAction and Params structs' properties were set, but the code I run had these lines commented:
colorConvertActionStruct->mMatchIntent = AC_UseProfileIntent;
colorConvertActionStruct->mConvertIntent = AC_UseProfileIntent;
colorConvertActionStruct->mEmbed = true;
colorConvertActionStruct->mPreserveBlack = false;
colorConvertActionStruct->mUseBlackPointCompensation = false;
colorConvertParamsStruct->mInks = NULL;
colorConvertParamsStruct->mNumInks = 0;
So, it seems that some unset properties in the structures were the reason of the crash.
My mistake..! Now I do further checks to be sure...