Saving a custom form errors with:
There's a slight problem
Journal Field can't be created because you reached limit number of 300 on journal fields.
Go to Setup > Interface > Update Feeds > click the All Fields sub-tab. Looking in the lower right will say "Showing ## Fields" You'll need to track less than 300. Find the fields you do not need to track and click the box to it's left > click Remove button along the top > Yes, Remove It.