The media profile update file is not signed when uploading .OMS file

I'm uploading a Substrate Preset to our L360 via the Web Access>Import dialog. When I receive the "file is not signed" error, I proceed to the printer’s front panel to accept the installation of the package (like I always do when installing a new OMS), but after the installation completes, the new Media Preset is not visible at the printer's front panel. I've installed dozens of OMS files this way in the past, but this time it's not working. Has anyone experienced this problem?

Hello @DanLong

Try to uninstall some profiles, and reinstall the OMS file you want to install. In case this action doesn't work, try to install the printer's firmware again.