We have fixed a lot of issue related to CodeView getting blank, can you please try the latest update Dw 17.5 and update this thread with your observations?
An error occurred while saving the commentAnonymous commented
September 2018, having this issue with 18.2. I can open 4-5 files at a time, and then they start opening blank in code view. Must restart Dreamweaver in order to fix. (And can still only open 4-5 files at a time.) Sometimes it happens with fewer files open, requiring Dreamweaver restart.