Showing errors in kamailio syslogs for Register messages - sip

Question

I am getting the below Error messages in syslog. Can anyone tell me why these two methods getting failed. Is there anything I am missing to configure in SIP phone.
ERROR: {1 2 REGISTER 619499693} [core/parser/parse_methods.c:456]: parse_methods(): Invalid method
ERROR: {1 2 REGISTER 619499693} [core/parser/parse_allow.c:65]: parse_allow_header(): bad allow body header
The captured register message below:
REGISTER sip:77.10.86.8;user=phone SIP/2.0
Via: SIP/2.0/UDP 77.10.86.9:5060;rport;branch=z9hG4bK1290987256
From: "USER1" sip:90000001#77.10.86.8;user=phone;tag=822848271
To: "USER1" sip:90000001#77.10.86.8;user=phone
Call-ID: 619499693
CSeq: 1 REGISTER
Contact: "USER1" sip:90000001#77.10.86.9:5060
Allow: INVITE, ACK, OPTIONS, BYE, CANCEL, UPDATE, INFO, SUBSCRIBER, NOTIFY, MESSAGE, PRACK, REFER
Max-Forwards: 70
User-Agent: eXosip/3.6.0
Expires: 3600
Supported: eventlist, replaces, tdialog, timer, 100rel
Allow-Events: dialog, message-summary, refer, reg, ua-profile
Content-Length: 0

Answer 1

The from and to headers do not comply with rfc3261 syntax:
From: "USER1" sip:90000001#77.10.86.8;user=phone;tag=822848271
To: "USER1" sip:90000001#77.10.86.8;user=phone
When a display name is used, the URI needs to be enclosed between <>
From: "USER1" <sip:90000001#77.10.86.8;user=phone>;tag=822848271
To: "USER1" <sip:90000001#77.10.86.8;user=phone>
You will find more details in rfc3261.
EDIT:
I was too fast in answering. The error mention a wrong value in Allow header. SUBSCRIBER (typo for SUBSCRIBE) is not defined by any specification. However, in rfc3261, such values (unknown) are allowed by the specification, and such header is correct from a syntax perspective.