So, It's back to 8.3 then..

same problem here…never had it before with ANY other version back to 3.7. same system has run v6/6.5/7/7.5/8 with no crash on exit. this is definitely a cubase 8.5 issue NOT the system.
THIS IS NOT A FEATURE BUG that can wait for a fix.
THIS IS A FUNCTION BUG that should be addressed immediatley. (not 3 months from now)
when a customer pays full price for a product they expect to get the full product cycle useage from the product.
this bug makes the software unuseable in a professional environment. waiting for an extended period of time for a fix results in being unable to use the product that was paid for. please issue a hotfix as soon as possible. clients expect to see current software when they are paying for a service. this crashing software cannot be displayed to a paying client.