Steps to reproduce:
Install newest Orion-RC.
The only extension installed thus-far is uBlock-Origin, from the same "Popular Extensions" menu. uBlock has not been configured.
Open Orion-RC menu, Popular Extensions.
Click to install Keeper.
The button turns white, but does not transition to Install.
Click it again, Cancel flashes and it reverts to "Get."
Other extensions are installable; see video.
Keeper installs or a message that it cannot install is displayed.
Orion, OS version; hardware type:
Version 0.99.124.4.3-rc (WebKit 6188.8.131.52.1)
MacBook Pro (macOS Ventura 13.4 build 22F66)