that's ok - just that i had the same issue here, where end users added their own columns to the portlets that were set up the same way as yours - eventually i figured out that it was the placement of those @ filters that was making things break, exactly with that 500 internal server error. I suggest you might have a look through 'Dave' s and 'maxad's suggestions on the sql wrap approach, on these forums. They are experienced fellows. In any case, if you still have that users browser logged in, you should be able to select one of their 'old' pages that they were looking at, get to the configure, General Properties, Restore Defaults, Save, List Layout, Submit, to get back to the last -published state of the portlet, without pushing it out from studio. ie. this is a 'pull' of theportlet's default settings by the one user, instead of a 'push' via studio.