Within the App Store app/Purchases, the grey button (on the right) says “Open”. But not always. I have 2 apps that persist in saying “Install”, even though I have verified the current version and clicked on the Install button and thus reinstalled as suggested.

So, how do I get the button to correctly say “Open”?

AFAIK, I have no specific problems/issues with this condition, but I prefer it be resolved. Or is this just a nit/bug that is best forgotten?

I don't know if this applies to your situation, but read Tackle Pro Video Formats 2.0.1 always appearing in Software Update.

I had a similar issue with a version of iMovie. It was persistently current and not current. I clicked "Install" whenever it was available and eventually it changed to "Open".

When all else fails, restart. A Package component may not have gotten cleaned up during the installation.

Alas, I have tried, without success, all the solutions/fixes so far presented.

And while joy eludes, my appreciation for the suggestions remains.

Perhaps after these two recalcitrant apps have been updated, things will again be put to right.

FWIW: The two apps to which I refer:
1) iMovie v10.0.8
2) Inerzia Timer v2.3.3.

You might try deleting the two apps and then reinstalling from the App Store.

Bingo!

The secret (and step I had missed) is that one must first delete the recalcitrant app and then reinstall.

Thanks, Joe. Now I can get back to working the easy stuff, e.g., addressing the Grand Unified Theory, etc.

I can second JoemikeB’s fix after having run into this issue with a free/donationware app I had downloaded from MacUpdate a while ago. This was a direct download, not involving a referral to the App Store, despite the fact that the download button on the developer’s web site points to the App Store. Some time later the App Store ‘noticed’ the app’s presence and listed an update. Problem was, the update was listed under my username, but with somebody else’s email address, which I couldn’t correct. I had to quit the App store, delete the app and reinstall from the App Store, now without the email address glitch. I have not noticed any untoward activity on my (strong password protected and regularly checked) Apple account, so it really looks like a glitch, not a hack.

As may have been surmised, the two apps that gave me grief, were originally stand-alone installs. Only later were they offered & updatable (solely) via the App Store.

Perhaps the issue indeed relates to how the app was initially installed.

Curious and curiouser...