When I try to publish the solution, I get an Error
1:PreEvent step registration does not support Post Image.
Don't know what to do. I just wanted to hide a Button in the RibbonBar
This worked. Thanks :)
This sounds like you have an invalid plugin registration step in your solution. Create a solution that just contains the entity that you wish to customise and load that into the ribbon workbench. See http://ribbonworkbench.uservoice.com/knowledgebase/articles/169819-speed-up-publishing-of-solutions