Try to start Thunderbird in safe mode. https://support.mozilla.org/kb/safe-mode-thunderbird

Does the problem go away?

I tried safe mode and it has the same spacing problems

In a different thread I solved how to use the userChrome.css file. But I can't get and css code that effects the line spacing in the message pane and the folder pane. Any ideas of how to do this?

I suggest you keep to a single thread, really it is the same half dozen folks that will answer you and having multiple thread just confuses the issue.

In this instance please post a screen short of what this double spacing looks like. hve you looked in you add-on manager to see if you had an add-on that used to manage this, or a theme that changed to look of Thunderbird?

I recall years ago lots of folk complaining about increased spacing, but I have seen nothing recent.

The other thread was marked solved before you wrote your comment above, if you would have looked at it. Its purpose was served in that I found out how to use the userChrome.css file, which is a different question than my more general question in this thread. I am open to any solutions here, css files or other.

blooski said

The other thread was marked solved before you wrote your comment above, if you would have looked at it. Its purpose was served in that I found out how to use the userChrome.css file, which is a different question than my more general question in this thread. I am open to any solutions here, css files or other.

Funny, I did read it, I even considered commenting on it yesterday. I am now quite please I did not. Nor will I be spending any further time on this thread. I asked for information I got a snide reference to my ability to read your other thread but exactly nothing useful in the way of information. I am done here and with you.

Just as well as you seemed to have only critical remarks and nothing of value to offer.

I have the same problem. Double spacing. I found a way to sort it but has to be done every time I write a new email. Open 'write'. Then you need your cursor on the message bit, not 'To' or 'Subject.' A wee box on the left says "Paragraph." open that and pick the top one, "Body text." Problem solved. Single spacing. But the stupid programme will revert you back for your next message so you have to do this every time. Hope this helps. Written by a simple mind who does not understand all the high falluting tech speak.

HectorLT,

Please start a new topic for your problem. https://support.mozilla.org/questions/new

I finally did come up with a half way solution, which was to restyle the page to a way that I find acceptable using the css in the userChrome.css. I had to research to find css statements that worked with chrome and play around with it a bit.