Bug 768919 changed the message theme used in Thunderbird by default and added (unintentionally I think) these 2 lines in Info.plist:
5.36 + <key>DefaultVariant</key>
5.37 + <string>Normal</string>
This causes the message theme system to attempt to include a Normal.css file that doesn't exist.
Created attachment 692766 [details] [diff] [review]
Remove the two lines.
Comment on attachment 692766 [details] [diff] [review]