Hello,  There was a change in the 7.0 Firmware that validates not only the length of the CHAP username,  but also to check for invalid characters.   This is in the 7.0 release notes:  Per the CHAP spec a Username can be up to 63 with ASCII characters (alphanumeric, dot, dash, and underscore).    You would either need to change the IQN name on the server, or jus change the CHAP credentials to remove the ":"   Regards, 
One of our clients use colons in the CHAP user names for enabling access on specific volumes. This is because they use the IQN of the server as CHAP user name.  They upgraded the firmware of one of their PS arrays and since version 7 you cannot enter colons anymore. Is it a bug or is it by design?
Colon in CHAP user name