In my original Zope installation, I'm still getting the same EOFError when I try to view a document containing <dtml-call FSSession>. I have been unable to reproduce the original TransactionError in the original Zope. I have mucked around with the 1st Zope since receiving this initial TransactionError - mostly removing var/Data.fs, etc.. and reinstalling FSSession etc... so that I could start "fresh".
You can correct the first Zope installation by doing the following. Remove <dtml-call FSSession> and instead use <dtml-var SessionUID>. This will give you the problematic unpicklable session uid file and just remove it. It should be ok after that. Don't spend time on it , I have a pretty good idea what is going on. I hope by tonight to have a fixed version out.
Pavlos
Joy! Following Pavlos's advice, my EOFError seems to be cured on my original Zope installation. Funny though, I fired up the original Zope and immediately used <dtml-var SessionUID> which gave me a KeyError - understandable since I had not started FSSession yet. Realizing this I did a <dtml-call FSSession> and Voila - it worked without having to remove any session files. Thanks for the help, Brian