I don't know about that error, but I have just started getting one myself. I'm using Slic3r 9.9 and RH 85b, also.
When running Slic3r outside of RH Here is my error:
Attempt to free unreferenced scalar: SV 0x18e7ffa4, Perl interpeter: 0x18750474 at C:/Users/.../.../slic3r-mswin-x86-0-9-9/slic3r/lib/std/thread s.pm line 101
I get the error right after I load an STL After hitting ok another error box pops up saying pretty much the same thing. Then Slic3r crashes after I tell it to slice. None of my stls work now. They all give pretty much the same errors...only the numbers are different after the SV and Perl interpeter.
Everything was working fine until I tried to direct RH to make slic3r 9.9 the default. Now, I got RH to make it the default, and everything seems to work fine when slicing inside RH. I'm just curious as to why I cannot Slice using Slic3r outside of RH now.
any ideas?
Thanks