Try posting your question at AMD ProRender MAYA Forum: Maya
Here are a couple of Threads of Users having a installation issue with Maya at AMD Forums for Prorender MAYA. Both are MAC Users:
RadeonProRenderv2.8 cannot be installed
RadeonProRender for Maya (v2.9) cannot be installed - This thread one of the ProRender's AMD employees gives instructions on trying to get it installed correctly.
What is the Make & Model of your GPU and Windows or Linux or MACOS version?