If only I'd have done it from the begining!
Hi All*,
Like myself, I can see it's the same with MANY of you trying to upgrade to WB5, if only someone had suggested THIS first!, I'd have saved a lot of headaches. In no way am I and expert on software or Stardock. Although the steps I have below are probably posted somewhere else, if so, I hadn't found it and I was pulling my hair out trying to figure out what to do. 
Then I tried this:
As long as you do have Object Desktop, and have gotten the "upgrade to WB5" pop-up, try this BEFORE trying to upgrade;
1. UNINSTALL your previous version of WB first
1b. If there are any program files left over after uninstalling, delete them
1c. If, like me, you'd like to keep all of your themes, simply rename the file/folder to something like "my themes"
2. After all of the prior version is uninstalled; reboot
3. Before running Stardock Central again, make sure there is NO WindowBlinds folder
4. Once everything is gone, now run Stardock Central again.
5. Then, go to the Object Desktop program's list (don't use the pop-up)
6. The newest Beta version should be on the top of the list, click on it, and Install
7. Reboot BEFORE applying any theme
After rebooting, go ahead and run wbconfig, and apply whatever theme you chose.
All should work well! Go ahead and move whatever themes you'd saved, back to the "new" WindowBlind folder.
Hope this helps!
JoeyLee*