I'm having a bit of a headscratch with this.
1>UMmuSDK.lib(ActionArea.obj) : error LNK2005: "public: virtual bool __thiscall MFD::ConsumeKeyImmediate(char *)" (?ConsumeKeyImmediate@MFD@@UAE_NPAD@Z) already defined in orbiter.lib(Orbiter.exe)
1>UMmuSDK.lib(ActionArea.obj) : error LNK2005: "public: virtual void __thiscall MFD::WriteStatus(void *)const " (?WriteStatus@MFD@@UBEXPAX@Z) already defined in orbiter.lib(Orbiter.exe)
1>UMmuSDK.lib(ActionArea.obj) : error LNK2005: "public: virtual void __thiscall MFD::ReadStatus(void *)" (?ReadStatus@MFD@@UAEXPAX@Z) already defined in orbiter.lib(Orbiter.exe)
1>UMmuSDK.lib(UMmuSDK.obj) : error LNK2005: "public: virtual bool __thiscall MFD::ConsumeKeyImmediate(char *)" (?ConsumeKeyImmediate@MFD@@UAE_NPAD@Z) already defined in orbiter.lib(Orbiter.exe)
1>UMmuSDK.lib(UMmuSDK.obj) : error LNK2005: "public: virtual void __thiscall MFD::WriteStatus(void *)const " (?WriteStatus@MFD@@UBEXPAX@Z) already defined in orbiter.lib(Orbiter.exe)
1>UMmuSDK.lib(UMmuSDK.obj) : error LNK2005: "public: virtual void __thiscall MFD::ReadStatus(void *)" (?ReadStatus@MFD@@UAEXPAX@Z) already defined in orbiter.lib(Orbiter.exe)
1>UMmuSDK.lib(universal_mmu.obj) : error LNK2005: "public: virtual bool __thiscall MFD::ConsumeKeyImmediate(char *)" (?ConsumeKeyImmediate@MFD@@UAE_NPAD@Z) already defined in orbiter.lib(Orbiter.exe)
1>UMmuSDK.lib(universal_mmu.obj) : error LNK2005: "public: virtual void __thiscall MFD::WriteStatus(void *)const " (?WriteStatus@MFD@@UBEXPAX@Z) already defined in orbiter.lib(Orbiter.exe)
1>UMmuSDK.lib(universal_mmu.obj) : error LNK2005: "public: virtual void __thiscall MFD::ReadStatus(void *)" (?ReadStatus@MFD@@UAEXPAX@Z) already defined in orbiter.lib(Orbiter.exe)
Does UMMU.lib define an MFD or something?