Color tab settings are erased

Hey smart people of the industry,

i am about to bite in my table.
Repeatedly, i have the issue of settings in my color tab being erased.
I don't know if it is a bug.

i opened my green screen project on the edit tab this morning and

- the backdrop was there but
- the person in front (power window insert) was complete black.
- sound is there
- thumbnails are there

When i opened to the color tab,

things that work:
- LUT is activated
- mouse hover over Nodes show "primary balance, log grades, custom curves, 3D qualifier, power windows"
- power windows settings are correct
- curves settings are correct
- the AMOUNT of qualifier paths are correct
- despill checkbox is activated
- media is found
- alpha channels are there

- BUT -

- the values of all qualifier paths are now erased to R0 G0 B0
- all Matte finesse settings (denoise, clean b/w, in/out ratio) are deleted to 0.00
- LUTs thumbnail is not preselected
- all primaries settings are back to 0 (Temp, Cont, Shad, Sat)
- clip preview thumbs are all black
- image in Monitor is black (except of jpg. backdrop)
- VERY STRANGE: when i change the curve settings the image appears again even when i return to the starting point, except in this case where the image is grey (because all of my qualifier settings are 0 of course)

Things that could have caused it:
i opened the project without having my external drives attached (where the raw footage is)
DaVinci said it could'nt find the paths.
i reopened and relinked, started new but nothing helps.
any idea how i get my settings back?

Thank you guys in advance!!
axel

specs:

Asus MS Laptop
intel core i7-7700HQ CPU
2.8 GHz
16 GB RAM
64 BIT
NVIDIA GeForce GTX 1050
Intel(R) HD Graphics 630
DR Version 17. OB Build 6