trigger_catapult is an entity that exists in TF2C, however, it is not in any of the provided Hammer .fgd files, causing it to appear as an obsolete entity in Hammer. Note that the TF2C catapult is currently missing some features compared to live TF2 such as being able to launch physics objects ( https://github.com/tf2classic/tf2classic-issue-tracker/issues/160 ), so keep that in mind for now and future updates.
Notice how SmartEdit is greyed out and none of the keyvalues have proper titles or options.
trigger_catapult is an entity that exists in TF2C, however, it is not in any of the provided Hammer .fgd files, causing it to appear as an obsolete entity in Hammer. Note that the TF2C catapult is currently missing some features compared to live TF2 such as being able to launch physics objects ( https://github.com/tf2classic/tf2classic-issue-tracker/issues/160 ), so keep that in mind for now and future updates.