How much music in DEX 3, how much system RAM? I’ve also seen a corrupt user profile cause this issue (where DEX 3 can’t save anything). A permissions issue preventing DEX 3 from “writing” data to documents, where the PCDJ-DEX3 folder resides.
The issue with the crash: Keep in mind you shouldn’t use any other applications while running DEX 3 during live performance – that’s a big live performance computer ‘no no’ in general, but more importantly, if the other application needs to access your graphics card like karafun will do it can cause issues with DEX 3. DEX 3 runs in it’s own environment very much like a ‘game’ does – and thus runs all graphics processing (from interface to extended display) through the graphics card/driver. The interface is “drawn” by the graphics card. Thus, anything else accessing it like karafun will and eating into graphics resources could certainly cause a problem and/or a crash.