Starting from SDM 17.4 RU 2, the two buttons above the description field (Spelling and Search Knowledge) are missing.
Service Desk Manager 17.4 RU2 and RU3
Starting from 17.4 RU2, Rich Tech Editor has been implemented which impacted the Spelling and Search Knowledge buttons.
Regarding the Spelling button:
This button has been removed because it will not provide exact results with HTML text with tags. We rely on the browser's built in spell checker.
Regarding the Search Knowledge button:
The Search Knowledge has challenges with the new RTE (Rich Text Editor), which requires us to enhance the code. This was enhanced and the changes would be available in the upcoming roll-up 17.4 RU 4.