Its possible that some users after Windows Update automatically download this element (KB4577586) which deletes Adobe Flash Player from your system. After, it might be possible, your system to crash when trying to enter to some RLC props with old scripts with flash.
a) Download again Adobe Flash Player into your system. Then you download (or repair) Utherverse/RLC client. Reboot your PC system. [recommended]
b) Restore your windows to previous date, without loosing your data.
In any case, you may report to UV/RLC your technical problem (they are already aware about it) and inform Noir Palace for your technical problem.
We try to assure that NONE will have such a problem unsolved within a few hours.