The workaround is a bit tricky, but here are the steps:
- Start a new meeting
- Start a local recording, let it run for about a minute
- End the meeting
- The popup that shows the progress of the recording finalizing will appear. Quickly, before this conversion completes, close the popup. This will make the recording uncomplete, so it will have the "Double-click to convert" files stored in the recording folder
- Navigate to Documents>Zoom and find the latest recording folder that has these unfinished conversion files.
- Delete these files
- Navigate to the folder that has your other "double-click to convert" files from the 90 minute meeting
- Copy these files, and paste them into the newest recording folders (where you just deleted the brand new "double-click to convert" files
- Go to the Zoom app, then go to Meetings>Recorded and go to the latest recording
- There will be a Convert button, so click on that
- Zoom will now start converting the recording files from the 90 minute meeting that wouldn't convert before.
Note, this trick is only applicable when "double-click to convert" files have trouble converting. In your case, if the finished video is only 10 seconds long, then it might have been an issue with the actual recording, and this fix wouldn't help.
It may also be the case that there are multiple recording files stored in your folder from the 90-minute meeting--one that's 10 seconds, and another that holds the whole 90 minute recording, so be sure to double-check that.