I wanted to install Firefox using the App Center. When clicking on it in order to install, a dialogue "Install non-curated app?" comes up, which is fine. But when I click "Install Anyway?", nothing happens. The App Center seems to be frozen. I can also not close the dialogue or the App Center window; it does not even close when I do a context-click in the dock and choose "close all".
Any idea why it is going wrong? I have installed before several other applications without any trouble.
The issue can't be reproduced. I located the appcenter process (using htop), killed it, restarted it and tried the installation again, and now it works.
My elementary version is 5.0.0-37.