Mine's Fixed !
I had this problem too, with CSS Menu Writer 2.0.5 reporting 'Error generating menu (wa.generate.menu): Process type "undefined" not found' when trying to generate a new menu or change an existing one.
After doing the recommended stuff several times - deleting the WinFileCache file and removing/re-installing WA extensions - I was still receiving the same error. Had to get the darn thing working, so I took drastic action ... be aware that this may not be recommended for YOU, but it worked for me :-)
I know that WA products work well ;-) , so after spending a lot of time using DW's capabilities to get a starting point on what was going wrong, I felt that the problem had to be caused by either js libraries interfering with each other, or caches bogging up the works. Unfortunately, (shame on me!) I did two actions at the same time and can't say which one fixed the problem (or whether both did, combined), but my gut feeling is that deleting the site cache did the trick.
So here's what I did - but I take no responsibility whatever for whatever happens with your system. I don't know how this could affect working on existing and established sites. And I'm nothing to do with WebAssist !
That's the disclaimer done!
Firstly, remove all WA extensions from DW, restart DW and then close it down. Delete the 'WinFileCache-xxxxxxxx' file as described in common_installation_issues.pdf .
Also located within the 'Configuration' folder is the 'SiteCache' folder ... make a copy of the 'SiteCache' folder so that you can restore it if you have any (other) problems later on, then open the 'SiteCache' folder and delete the folder for the site that you have problems with. For example, on my system (Windows 7 & DW5) if I had problems with the menus on 'MySite', I would delete the folder "AppData/Roaming/Adobe/DreamweaverCS5/en_US/Configuration/SiteCache/MySite".
Theoretically, you should be able to delete all remaining WA files, but DW extensions are still a dark art (to me) - so if it's not obviously for a WA extension, my advice is to leave it alone. Anyway - you've taken a backup of the folder, right? Good!
Once done, reinstall your extensions - trying to achieve some logical kind of build order. I tested EVERY extension after each new installation - so install 'a' ... test 'a'. Install 'b' ... test 'a' + 'b' etc.
Build order was:
1. CSS Sculptor
2. Web Standards Advisor
3. CSS Menu Writer
4. DataAssist + support fix
7. Power CMS Builder (beta)
9. Image Re-sizer
All working (actually better than ever) and I'm a very happy chappie, getting going on the site that I should have started a week ago!
Please remember that this is a very cavalier 'fix', probably not endorsed in any way by WebAssist. It's drastic (and I can already hear the 'Tut! Tut's!' reverberating around the 'net). Don't try it if you're not confident of your abilities.
So, I might be slightly ashamed of using such bad working practices ...
... but mine works :-)
WebAssist - taking into account every kind of niggly problem that occurs with sophisticated software like this, maybe there is a need for a cleanup utility that Customers can use? I'm sure your developers will already have one somewhere. Might drastically reduce your support costs, too.
Best of luck everyone!