Export Selected Events greyed out/not available

While working on a project, all of a sudden, I am unable to “export selected events” from the export menu. was working fine, now when I select events to export, the option is “greyed out” and not available.
Anyone know why this could have changed?
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I know this is an old one, but seeing as it came up when I googled to try and solve this issue: make sure the track that the selected events are on isn’t muted.