The FArchiveMemoryStream class is defined in GeneSplicerModule and RigLogicModule.
This generate linker error as this doesn't respect the "One Definition Rule"
1>Module.GeneSplicerModule.cpp.obj : error LNK2005: "public: __cdecl FArchiveMemoryStream::FArchiveMemoryStream(class FArchive *)" (??0FArchiveMemoryStream@@QEAA@PEAVFArchive@@@Z) already defined in Module.RigLogicModule.cpp.obj
1>Module.GeneSplicerModule.cpp.obj : error LNK2005: "public: virtual void __cdecl FArchiveMemoryStream::close(void)" (?close@FArchiveMemoryStream@@UEAAXXZ) already defined in Module.RigLogicModule.cpp.obj
1>Module.GeneSplicerModule.cpp.obj : error LNK2005: "public: virtual void __cdecl FArchiveMemoryStream::open(void)" (?open@FArchiveMemoryStream@@UEAAXXZ) already defined in Module.RigLogicModule.cpp.obj
1>Module.GeneSplicerModule.cpp.obj : error LNK2005: "public: virtual unsigned __int64 __cdecl FArchiveMemoryStream::read(char *,unsigned __int64)" (?read@FArchiveMemoryStream@@UEAA_KPEAD_K@Z) already defined in Module.RigLogicModule.cpp.obj
1>Module.GeneSplicerModule.cpp.obj : error LNK2005: "public: virtual unsigned __int64 __cdecl FArchiveMemoryStream::read(class trio::Writable *,unsigned __int64)" (?read@FArchiveMemoryStream@@UEAA_KPEAVWritable@trio@@_K@Z) already defined in Module.RigLogicModule.cpp.obj
1>Module.GeneSplicerModule.cpp.obj : error LNK2005: "public: virtual void __cdecl FArchiveMemoryStream::seek(unsigned __int64)" (?seek@FArchiveMemoryStream@@UEAAX_K@Z) already defined in Module.RigLogicModule.cpp.obj
1>Module.GeneSplicerModule.cpp.obj : error LNK2005: "public: virtual unsigned __int64 __cdecl FArchiveMemoryStream::size(void)" (?size@FArchiveMemoryStream@@UEAA_KXZ) already defined in Module.RigLogicModule.cpp.obj
1>Module.GeneSplicerModule.cpp.obj : error LNK2005: "public: virtual unsigned __int64 __cdecl FArchiveMemoryStream::tell(void)" (?tell@FArchiveMemoryStream@@UEAA_KXZ) already defined in Module.RigLogicModule.cpp.obj
1>Module.GeneSplicerModule.cpp.obj : error LNK2005: "public: virtual unsigned __int64 __cdecl FArchiveMemoryStream::write(class trio::Readable *,unsigned __int64)" (?write@FArchiveMemoryStream@@UEAA_KPEAVReadable@trio@@_K@Z) already defined in Module.RigLogicModule.cpp.obj
1>Module.GeneSplicerModule.cpp.obj : error LNK2005: "public: virtual unsigned __int64 __cdecl FArchiveMemoryStream::write(char const *,unsigned __int64)" (?write@FArchiveMemoryStream@@UEAA_KPEBD_K@Z) already defined in Module.RigLogicModule.cpp.obj
1>D:\P4\UE5\Gym5Main\Binaries\Win64\Gym5Main.exe : fatal error LNK1169: one or more multiply defined symbols found
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-349274 in the post.