You can check the latest version with in the DugiGuides Installer, the Members area, and In-Game.
Dugi Guides Installer
Dugi Guides Members Area
In-Game
ESC > Addons
Look for DugiGuidesViewer 9.0193
..or which ever version you may have.
I hope the pics help.
If you indeed have 9.0193, then can you please try with just Dugi Guides enabled. All other addons disabled for now.
Though I have tried to replicate this error and I am currently looking in to the function the error above describes. I am also in contact with Dugi to see if we can find a prevention. Something may be interfering with DugiGuides or it might of have been a case of bad luck at the time, this sort of thing does happen, not just in WOW. What ever it is, we’re looking in to it and hopefully we can come up with a solution.