Issues with Form Builder

Dear Sandra and Ross,

I created a duplicate of this years student application form, to be used for mid-year enrollment.

After going to System Admin/Form Builder/Edit Form/ Design, I was unable to edit or delete any of the fields.

I tried creating another form and after creating a page, I was unable to add any fields or delete the form.

System info is below.

System Overview
Gibbon Version: v28.0.01
PHP Version: 8.3.14
MySQL Version: 10.6.20
MySQL Collation: utf8mb3_general_ci

After doing considerable troubleshooting, I discovered that the problem was in the custom theme that I had created when using v26.

Since v28 has a different UI, I had to create a new custom theme which solved the problems.