I recently upgraded UltiMaker Cura from version 5.2.1 to version 5.9.0 and when I did it loads models very slowly, or better said, it has a long delay loading the model. I was not getting this delay in version 5.2.1. After some internet researching I learned that it was a preinstalled Marketplace Extension called USB Printing that was causing it. So to solve this delay, if you don't need USB Printing, you simply just disable it.
First open Cura and in the upper right you'll see a button labeled MARKETPLACE. Click on it.
Clicking on MARKETPLACE opens this Marketplace window. Now click on the GEAR ICON (see red arrow in below image).
Once you've clicked on the Gear Icon you'll see a list of preinstalled extensions one of which is called USB PRINTING. Simply click on the DISABLE button beside this extension to turn it off. In the below picture it is turned OFF (blue button labeled "Enable" means it's OFF, black button labeled "Disable" means it's ON)
Now simple Close and Restart Cura and your models will load much faster without an annoying delay.
NOTES: I am using Ubuntu 24.04.1 and I was getting this delay behavior in bother the APPIMAGE and FLATPAK versions of Cura. Cura Version 5.2.1 does NOT have this behavior. This workaround fixes this delay in both the Appimage and Flatpak versions of Cura.
