Hi All!
It’s possible to change MAC-username format by removing colons (like a RADIUS MAC-format)? Windows-based login name prevents using colons in username.. 
Yes. It works for RADIUS, but I haven’t checked it with the local router database.
/ip hotspot profile
set X radius-mac-format=XXXXXXXXXXXX
This change RADIUS MAC-format.. (Calling-Station-Id in radius packet), not login name…
It does change the login (user) name. I tested it, and it works.
Enable radius debug logging, and you will see the change in your router log.
/system logging
add topics=radius,debug action=memory
no, you wrong
Network Policy Server denied access to a user.
Contact the Network Policy Server administrator for more information.
User:
Security ID: NULL SID
Account Name: 00:1A:1D:00:67:75
Account Domain:
Fully Qualified Account Name: \00:1A:1D:00:67:75
Client Machine:
Security ID: NULL SID
Account Name: -
Fully Qualified Account Name: -
OS-Version: -
Called Station Identifier: hotspot1
Calling Station Identifier: 001A1D006775
on 6.7 RouterOS version…
Yes, I am wrong. I just tested it with V6.9 and it does not change the mac format. It leaves the colons in the mac address. Sound like a new bug to me.
I think the last time I tried this was with V4.X, so it has been a while. It did change the format then. I remember this because my radius didn’t like the colons either.
edit: I sent an email to support asking about this. I’ll let you know what they say.