Might be worth checking what happens there.
If the same issue also happens there, then we know it isn't specific to Opus and it's best reported to Tracker so they can look into it.
But if it only happens in Opus, it might be something we're doing wrong on our side.
When things are stuck, taking a few process snapshots of prevhost.exe, as well as dopus.exe and any docsvw32.exe / docsvw64.exe processes may reveal where things are stuck.
(Remember to make more than one snapshot of each thing, as per the instructions.)