You’re right… my mistake, it is in the 2.1 version.
This option will only work with server URLs on the same origin (host and port, meaning the openHAB server), that is, relative URLs like “/static/mystylesheet.css”. URLs coming from the Internet like a CDN, or another server will be blocked.
Thats the case, I did the instllation exactly the way it was described in the other thread. But still it is not applied . Any suggestion how to check if habpanel can find the file? (Copied them via the shares defined in the openhab documentation)
did it by checking if I see the file using sudo nano. Found out that something went wrong during copying files. folder was names matrix-theme.css (in Finder the folder was named matrix-theme) and wasn’t possible to delete via SSH. By removing it in the samba share an copying everything again, it is working now