"Resolve failed to save"

this after pasteing a timelines between projects
- the source project had the media indexed,
- related media was imported into the target project when the timeline was pasted
- the imported timeline is running cleanly in the target project
- if i cut the imported timeline into an existing timeline Resolve throws up "Resolve failed to save" error
- at that point it appears the project is bricked, it cannot be saved, and a DRP made from it is 8kb...
- Ctl+z will not undo to get the project back into a savable mode
- only option is to quit without save and lose curent work
- the target project is now and forever trashed, it can be opened but it cannot be saved

this seems to be repeatable, this is the third time in the last week i've seen this behavior

i already make DRP's constantly so i've not lost any significant time/work, but if i was not in the habbit of saveing as often as i do, i'd have a very sad face....

also i see sys ram rise to v14 levels when doing this, Resolve alone useing 32gig, i have 128g so loads of headroom in my system, not likely due to lack of ram and flooding swap space