t bird mail receipt pop up causes win 7 to hang

T bird crashes when pop up appears in lower right announcing i have new mail. Following are some of the error msgs are in error console Could not read chrome manifest 'file:///C:/Program%20Files%20(x86)/Mozilla%20Thunderbird/chrome.manifest'. Could not read chrome manifest 'file:///C:/Program%20Files%20(x86)/Mozilla%20Thunderbird/extensions /%7B972ce4c6-7e08-4474-a285-3208198ce6fd%7D/chrome.manifest'. Timestamp: 6/24/2015 8:03:14 PM Error: pop.verizon.net : server does not support RFC 5746, see CVE-2009-3555 Timestamp: 6/24/2015 8:03:14 PM Error: pop.verizon.net : server does not support RFC 5746, see CVE-2009-3555 Timestamp: 6/24/2015 8:06:42 PM Warning: Unknown property '-moz-border-radius'. Declaration dropped. Source File: mailbox:///C:/Users/x/AppData/Roaming/Thunderbird/Profiles/pqal1h63.x/Mail/incoming.verizon.net/Inbox?number=4847225 Line: 0, Column: 57 Source Code: background:#81bc2f; border-radius:6px; -moz-border-radius:6px; -webkit-border-radius:6px; border-bottom:2px solid #548323; color:#fff; display:block; font-size:17px; font-weight:bold; height:42px; line-height:42px; padding:0 30px; text-align:center; text-decoration:none; text-shadow:1px 1px 0 #426319 Timestamp: 6/24/2015 8:03:22 PM Warning: Unknown property 'mso-table-lspace'. Declaration dropped. Source File: mailbox:///C:/Users/x/AppData/Roaming/Thunderbird/Profiles/pqal1h63.x/Mail/incoming.verizon.net/Inbox?number=4841816 Line: 0, Column: 42 Source Code: border-collapse:collapse; mso-table-lspace:0pt; mso-table-rspace:0pt; background:#eaeff2; line-height:100%; margin:0; padding:0; width:100% Timestamp: 6/24/2015 8:03:22 PM Warning: Unknown property 'mso-table-rspace'. Declaration dropped. Source File: mailbox:///C:/Users/x/AppData/Roaming/Thunderbird/Profiles/pqal1h63.x/Mail/incoming.verizon.net/Inbox?number=4841816 Line: 0, Column: 64 Source Code: border-collapse:collapse; mso-table-lspace:0pt; mso-table-rspace:0pt; background:#eaeff2; line-height:100%; margin:0; padding:0; width:100% Timestamp: 6/24/2015 8:12:39 PM Error: pop.verizon.net : server does not support RFC 5746, see CVE-2009-3555