Until today I had no problems. Starting today, I can send emails but I can't receive them. I've checked all the settings, ran a virus scan, scanned for malware, disabled the virus software, and have reinstalled Thunderbird with no change. Here is the error console log with just the errors, there were a number of warnings and information entries as well: Timestamp: 12/14/2015 2:57:24 PM Error: downloadable font: kern: Too large subtable., table discarded (font-family: "Open Sans Light" style:normal weight:normal stretch:normal src index:1) source: https://mozorg.cdn.mozilla.net/media/fonts/OpenSans-Light-webfont.1c8075cacedb.woff Source File: https://mozorg.cdn.mozilla.net/media/css/thunderbird-start-bundle.08a09d25e7a1.css Line: 1, Column: 36 Source Code: @font-face { font-family: "Open Sans Light"; font-style: normal; font-weight: normal; src: url("/media/fonts/OpenSans-Light-webfont.804037562eab.eot?#iefix") format("embedded-opentype"), url("/media/fonts/OpenSans-Light-webfont.1c8075cacedb.woff") format("woff"), url("/media/fonts/OpenSans-Light-webfont.ecb4572a5e47.ttf") format("truetype"); } Timestamp: 12/14/2015 2:57:24 PM Error: downloadable font: kern: Too large subtable., table discarded (font-family: "Open Sans" style:normal weight:normal stretch:normal src index:1) source: https://mozorg.cdn.mozilla.net/media/fonts/OpenSans-Regular-webfont.2696e36f12c5.woff Source File: https://mozorg.cdn.mozilla.net/media/css/thunderbird-start-bundle.08a09d25e7a1.css Line: 1, Column: 1057 Source Code: @font-face { font-family: "Open Sans"; font-style: normal; font-weight: normal; src: url("/media/fonts/OpenSans-Regular-webfont.83efe33660ab.eot?#iefix") format("embedded-opentype"), url("/media/fonts/OpenSans-Regular-webfont.2696e36f12c5.woff") format("woff"), url("/media/fonts/OpenSans-Regular-webfont.3cbf4d3ed22e.ttf") format("truetype"); } Timestamp: 12/14/2015 2:58:11 PM Error: path is null Source File: resource://gre/modules/osfile/ospath_win.jsm Line: 220