At the top right of the Thunderbird window, click the menu button > Options > General > Language & Appearance > Fonts & Colors > Advanced

Please post a screenshot of your settings. https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

Here is a image

From the 'Fonts for:' drop-down menu select 'Other Writing Systems'. Does it have the same font settings as for Latin?

If not, use the same ones as for Latin.

here is what i get

the text in the message pain is way too small how can I make it bigger? thanks beau

Does holding the ctrl key and pressing the plus + key make it larger? Minus (-) and Zero (0) to reduce and Reset respectively.

Not permanent, but useful if it is just a couple of regular correspondents that insist you should read 10 point text.

A font size of 17 and 14 respectively should be sufficient. Do you still have a problem?

Hi What text I am trying to get bigger is the subject line

I had the upgrade installed automatically, ( turned off now ) the upgrade deleted all my email accounts all Locale folders and all my settings.The only thing that remained was my address book so I had to re-enter everything. It took me so long to get Thunderbird as I liked it. Since the upgrade 2 days ago, I have been trying get this new V78 as the old ver. I did try to go back but it said I could not as it was not compatible with Win 10, which cannot be correct as it was working ok before, I have my suspicions that there is a file installed with V78 that will not let you go back. I now have my Thunderbird install and all my email addresses set up with all my email in each separate email address. But lost all this below. 1: Can't resize my text ( stuck with 10 font) I did alter the text size by a new folder ( chrome.css ) this don't work anymore 2: Lost my inbox where all my 7 email addresses went into ( yes i have tried Folders > unified ) don't work. 3: Lost my Local folders where i kept all customer emails in separate folders. (about 2000 of them ) Ok it's only 3 things but has caused me many lost hours and all I have is the basic Thunderbird which works but not as i want. Has anyone else lost everything, same as me?