Quick answer
In classic Outlook, go to File → Options → Add-ins. At the bottom, set Manage: COM Add-ins → Go and tick LEAP. If it's not there, set Manage: Disabled Items → Go and re-enable it. Still missing? Check you're not in New Outlook — the LEAP add-in only works in classic Outlook.
WHY IT HAPPENS
Outlook quietly switched it off.
Outlook monitors how long add-ins take to load. If the LEAP add-in is slow to start — often after a Windows or Office update — Outlook disables it to "speed things up" and drops the tab without telling you. A crash or an interrupted update can also un-tick the add-in, and turning on New Outlook hides all classic COM add-ins like LEAP entirely.
THE FIX
Re-enable the LEAP add-in.
- Make sure LEAP is running and you're signed inOpen LEAP as you normally would and log in. The Outlook add-in talks to your running LEAP session — if LEAP isn't open, the button won't work even when it's visible.
- Open Outlook's add-in settingsIn classic Outlook, click File → Options → Add-ins. You'll see lists of Active and Inactive application add-ins.
- Re-tick the LEAP COM add-inAt the bottom, next to Manage, choose COM Add-ins and click Go. Tick the box next to LEAP (or "LEAP for Outlook") and click OK.
- Check the Disabled Items listIf LEAP wasn't in that list, go back to Manage, choose Disabled Items, click Go, select LEAP and click Enable. If Outlook prompts that a slow add-in was disabled, choose Always enable this add-in.
- Fully restart OutlookClose Outlook completely. If the tab still doesn't return, restart the PC — this clears any half-loaded Office process holding the add-in back.
- Rule out "New Outlook"If there's a New Outlook toggle at the top-right, switch it off to return to classic Outlook. The LEAP add-in does not run in New Outlook.
- Repair or reinstall as a last resortStill gone? Reinstall the LEAP Outlook integration from within LEAP (Help/Settings → install the Outlook add-in), or run Office → quick repair from Windows "Installed apps", then repeat steps 3–4.
Handy to know: if this happens to one person it's usually a local Outlook setting; if it happens to several people at once, it's more likely an Office update or a policy change that needs fixing at the source — worth flagging to your IT provider so it doesn't keep recurring.
