When starting Thunderbird in Ubuntu 20.10 an error message is displayed
XML Parsing Error: undefined entity
Location: chrome://messenger/content/messenger.xhtml
Line Number 905, Column 3:
<key id="openLightningKey"
--^
and nothing more happens. However Thunderbird can be started in "safe mode" with the command line command
thunderbird -safe-mode
I have a number of language packs installed, German, English (CA), English (GB), French and Swedish.
How can I make Thunderbird start OK from the apllications menu?