To @FinalLightNL , @Claudio4901, @PaulG4791
Out of curiosity, what version of Game Services are you using? Currently the latest version is 6.69.16001.0.
I exited the beta two days ago returning to SU9 1.26.5.0 and with the previous version of Game Services (6.69.15001.0) I got the warning “… insert disk” which I had corrected once in the SU10 Beta. Now, in version SU9 1.26.5.0 with the latest version of Game Services everything runs smoothly with no warnings, stuttering or and / or slowdowns.