MacOS Catalina / Big Sur Workaround

Apple have started requiring developer signatures in MacOS Catalina and Big Sur. This shows up as a warning box stating that plugin

The workaround for this problem is to remove the quarantine flag as follows:

  1. Install the plugin by following the instructions (effectively copying the MBR Color Corrector 3.plugin into /Library/Application Support/Adobe/Common/Plug-ins/7.0/MediaCore/).
  2. Open Terminal (for example, by opening Launch Pad and searching for Terminal)
  3. Enter the command
    cd "/Library/Application Support/Adobe/Common/Plug-ins/7.0/MediaCore/"
    and press Enter
  4. Enter the command
    sudo xattr -r -d "MBR Color Corrector 3.plugin"
    and press Enter
  5. Terminal will now ask for a password, the password you should use is the one for your user account for your Mac. (Because the command is editing a file in /Library/... Terminal needs to ask permission in the same way that Finder did when you copied the plugin a few moments ago).

After doing so, you may have to hold the shift key while starting Premiere Pro for the first time. (Premiere Pro has a plugin cache that may remember that the plugin didn't work, but holding down shift causes Premiere Pro will rescan all the plugins and update the cache).

Once you have verified that "MBR Color Corrector III" can be applied to a clip: you can be sure that these steps are complete (and therefore you don't need clear the cache again).

If you re-install the plugin for any reason, such as a upgrading to a newer version, you will have to repeat the steps on this page.