Because there is only one AT command interface with the modem, if the modem is busy processing another AT command (for example activating GmPRS or CS call), then another Terminal Equipment (TE) try to query information using AT command (in this case WebConsole), then most probably it will timeout or give error. Refreshing the web page will usually solve the problem. If not, wait for the SAT LED on the BDU has turned orange or green before retrying.