It should happen in less than a second. Since it doesn't, there may be a problem with your file or maybe just this one layout.
You can run a recover on the file and see if any problems are reported.
You can also delete the layout and create a new one from scratch. (Don't try to copy and paste objects from the problem layout as you may copy the problem along with the object you are copying.)
Things to keep in mind about Recover:
- Recover does not detect all problems
- Recover doesn't always fix all problems correctly
- Best Practice is to never put a recovered copy back into regular use or development. Instead, replace the damaged file with an undamaged back up copy if this is at all possible. You may have to save a clone of the back up copy and import all data from your recovered copy to get a working copy with the most up to date information possible.