I had also submitted a problem report to support. Upon investigation, I managed to figure out what is causing the hang and replicate in a small solution/Project I attached to this post.. But in summary, at least in my case, Slickedit will hang opening a solution file that has a Solution Folder that has the same name as one of it's Child Solution folders... So for example, in the case I attached, opening the sln in Visual studio notice that you have a top level Solution folder named "MyApplication" when you expand it in Solution Explorer, you will see a child Solution folder also of the same name, expanding that you see the project etc.. Slick Edit does not handle this it seems.