I created an API trace which reproduces the problem for me (https://dl.dropboxusercontent.com/s/hc6v7gdcshj4ljd/eu4.trace-lockup.xz?dl=0 , 120 MB, unfortunately trimming produces only invalid states). The shaders itself don't look to bad to me but I don't have any experience deducing a miminal testcase from an apitrace (pointers welcome).