Can download 68.1.1 here: https://www.thunderbird.net/en-US/. Close Thunderbird and install. Took a leap of faith, but it all worked, and now new messages are bold again.

TB 68.1.1. is a beta though, what are the possible problems?

Other than losing most of your extensions? The developers of my favorite extensions appear to have given up.

Yeah, I upgraded and the bold is back, but lost all my themes and extensions. Drag...

Anyone who has updated to 68 and found some add-ons have become incompatible should list them here. Many of the 'lost' add-ons have been updated or replaced by substitutes - although this information isn't always widely known.

Actually, I checked to see what other things might be available and there was like one thing that would work with this version.

JamietheFruit said

I'm new to this. How do I 'switch' to 68.1.1?

Search for "Thunderbird 68.1.1." Install.

Ditto on this problem - really frustrating.

Download 68.1.1 as mentioned above, you'll lose your extensions, but it works.

I downloaded 68, but I do not see my inbox or accounts from version 60. How do I migrate all my existing account information?

JKM said

I downloaded 68, but I do not see my inbox or accounts from version 60. How do I migrate all my existing account information?

Help/Troubleshooting Information, click about:profiles. Is there another profile that isn't the Default? If so, set it as Default and restart TB.

Excellent advice, everything is there now - and the bolding is back! Thanks!

My BOLD is back! Thanks!!