Your IMAP command could not be sent to the server

After two years of using Live Mail, last week I keep getting the below error. I have seven gmail accounts, all set up the same, but only my main account seems to blow up. I have searched high and low for solutions and none have worked. I do not consider POP3 as an acceptable alternative.  I have tried changing the ports, deleting/recreating the account etc. In internet searches I find nothing solid, just a lot of the the same problems. Amazingly, I searched Microsoft's Supported Products list and Live Mail was not on it. WFT. Will be changing back to Thunderbird or something equivalent.