Steps to reproduce:
1. Change all relative paths from "/EPiServer/" to "/manage/UI/".
2. Install EPiServer.XForms package (version 1.0.1).
3. Add a model and view for a block (called FormBlock) which contains an XForm property.
4. Create a new block with type of FormBlock.
5. Open the Select Form dialog.
Expected: The dialog opens as usual.
Actual: The dialog opens with an error, stating that it cannot find XFormSelect.aspx.