After I updated to the latest ROM - BV8000Pro_blackview_20170804 I cannot enter Developers Options anymore - I constantly get the following error message:

"Settings keeps stopping"
X Close App

I need to enable the USB Debugging and there is no other way to do this but in the Developer options. Please, advice how to fix this!

please try if a factory reset will help to solve this:

wipe data/factory reset in recovery (this will delete your data/settings):
- Power off and then press Power and Volume-up together for around 10 Seconds
- be sure that the little arrow point on recovery (select with volume up, enter with volume down)
- Then the open android with red triangle+"no command" is shown - press Power and Volume up together again
- Select Wipe data/factory reset with volume keys, confirm with power
- After factory reset select reboot system now

Please report if this solved your issue or not.

I tried this several times with no success unfortunately. I am still not able to enter developer mode.