Cannot create target: DymolaBlock in Simulink and MinGW-Compiler

I have to integrate a Dymola-Model into an existing Simulink-Model. I used to take the DymolaBlock for this. Unfortunately I cannot create the mex64-Target with the shipped MinGW-Compiler of Matlab 2018a. I only get the output that is shown in the attached file. Is there a known limitation with the DymolaBlock and MinGW-Compiler?

I also tested the Visual C-Compiler and it works. Unfortunately I have to stick to the projects toolchain and therefore I cannot use Visual C-Compiler in production use.