Here's ONE Work-Around ... (It WORK'd! for ME!):
After the GeekLog 2.0.0-(rc3) INSTALL ... (and before you login with your 'Admin' and 'password'

.
1. Run the following UPDATE-QUERY on your GeekLog-DATABASE:
<<<
update plugins set pi_enabled=0;
>>>
2. Login to your GeekLog 2.0.0-(rc3) with your default 'Admin' and 'password'.
3. Click the link "Plugins(6)" and MANUALLY Re-Enable ALL of your Plug-Ins.
-
The Extra-Performance was Immediately-Obvious AND I LUV the LOOKs!

of the ... 'Denim' Theme
AND
I was able to figure out how to get my Big-Grubby-Hands on the Forum-2.9.0 Code-Files !!!
You Geek-Guys need to maintain a Updated-(easily-found)-Download for the New-Forum-2.9.0 !!!
I'm beginning an install of Forum 2.9.0 as soon after I get this ... POST'd