In order to make NXRM more secure by default, we have disabled the scripting related features. This affects scripts as used through the Script REST API and through scheduled tasks.
Scripts which are present from an upgraded version will continue to be executable but their script source will not editable.
A detailed article covering this change is here:
If you need to re-enable adding and editing scripts, add this line to $data-dir/etc/nexus.properties: