Theme: when creating a Theme without a Program, an error is thrown and it disappear from the Grid

Issue Summary

When a Theme is created without a Program associated with it, an error is thrown and the Theme doest't appear on the Grid. If you search on throught the universal search (the magnifuing glass at the right corner of the screen), you can find the Theme, and if any update is made on it, the Theme will appear on the Grid after it.

Also if a Theme that is on the grid has the Program removed from it, it will throw an error and disappear form the grid as well.

Steps to Reproduce

1. Go to the Theme Grid
2. Hit Add Theme
3. Fill the details but don't add a Program
4. Save
5. To Find the Theme, click on the magnyfing glass on the right corner
6. Type its name, and open it
7. Edit any field and save

Expected Results

If the Program is not a mandatory field for the Theme, it would be created without errors.

Actual Results

An error is thrown and the Theme disappears from the grid.

Workaround

There is no workaround for the error, but you can find the Theme and update it to make it appear on the Grid:

1. To Find the Theme, click on the magnyfing glass on the right corner
2. Type its name, and open it from the list of items that appear
3. Edit any field and save