Extension Manager doen not show any extension

It seems like there is a problem with the extension manager. There is no extension seen at the extension manager. I thought it might be specific to me, but then I realized that there is an update on the software. For the one who has such issue and benefits from the link below (how to install extensions manually);


I am having the same problem - and even when I try to install the extension (SlicerRT) manually, it installs but then does not activate in the menus…running version 4.11.20210226.

Hi John,
After you install the extension (such as SlicerRT), you need to restart the 3D slicer. In general, it asks you to restart the software with an notification (located right bottom of the extension manager).


Yes, I know that is what is supposed to happen, but it does not: the restart button stays greyed-out. The error log shows: Uncaught ReferenceError: midas is not defined

Even if I restart the application anyway, the situation persists: SlicerRT appears in the “manage extensions” tab, but does not function - does not appear in the menus…

This is due to a temporary issue related to the extension manager server being upgraded. The workaround process is described here:

The simplest solution is to use the Slicer Preview Release. The Extensions manager has no issues in this version and it should generally work better than the latest Slicer Stable Release.