Worker name must be alphanumeric?

HOST: hub.miningpoolhub.com
PORT: 20575
Username: weblogin.workername

thats how username should look like so for me it would be "Airy.1" BUT I CANT EVEN NAME HIM "Airy1" caused miner name must be alphanumeric or "filed attempt to change". Im so much tilted, pls tell me how to fix it, cant think clearly.

Searched google both nicehash and miningpoolhub.com all forums obv. enought word think this problem is so easy and clear for all...... sorry to bother