I just had this same error; when I go to View-Ide Internals-Information About Used FPC, one section sticks out:
FPC executable:
Compiler=C:\lazarus\fpc\3.0.0\bin\x86_64-win64\fpc.exe
Options=
CompilerDate=2/14/2016 13:21:00
RealCompiler=C:\lazarus\fpc\3.0.0\bin\x86_64-win64\ppcx64.exe
RealCompilerDate=2/14/2016 13:21:00
RealTargetOS=win64
RealTargetCPU=x86_64
RealCompilerInPath=C:\lazarus\fpc\3.0.0\bin\x86_64-win64\ppcx64.exe
Version=3.0.0
CfgFilename=C:\lazarus\fpc\3.0.0\bin\x86_64-win64\fpc.cfg
It looks like the RealCompilerInPath is ppcx64? That doesn't look right.
I think there's a path problem (maybe caused by MSYS2?)