HI @Siamac_Mashod,
You shouldn’t, Rockna support should be able to assist with this clearing the cache was just a suggestion.
One other thing, I’m looking up the Rockna manual:
I see that it has a Web Interface option, can you check to see if you’re able to clear out the cache there?
If there is a reset database or reset Roon settings in the WebUI, I would give that a try, but first make sure you have a Backup of your Roon database somewhere safe.
I would also check the DNS settings on the Rockna WebUI, it might not be getting a valid DNS.