Overview
You have updated your Service Gateway environment to an early release of the v5.2 Beta but have encountered issues using the Script Editor. When you open a template within the Script Editor and attempt to test your script, you cannot enter a value within the unique ID field or select the Evaluate Script button.
Due to this trouble, you are unable to make any changes to scripts within your environment.
Solution
Within the early releases of the v5.2 Beta, the Script Editor testing functionality was not yet implemented within the new HTML5 UI. This missing functionality was finalized and included as part of the final release of Service Gateway v5.2 (5.2.0.0.305).
To resolve this behavior with the Script Editor, please deploy the final version of v5.2 within your environment. See the version 5.2 release notes for installation instructions.