Black background on text when receive an answer

I think having more specifics will help. Such as: - Does this happen ONLY for email from Outlook email accounts? - If true, does this happen for ALL Outlook email accounts? - What version are you using of Thunderbird? - What theme are you using? - Does this happen when all addons are disabled? - Do you have any CSS content in userControl or userContent files?

Knowing that will help isolate where the issue might be. Thank you.

Hi David, Thanks for the help.

- All the mails that i saw with this problems was from outlook users.

- No it doesn't happen with all outlook users.
- Several users in my company have the problem, we have two thunderbird version in use and both meet the problem 102.10.0 and 45.8.0

- Theme used in 102.10.0 is the "System theme", but i try to change it by dark, it doesn't change anything. - Same issue with all addon disabled. - I'm not sure for the last question. I have an user.js file but I have nothing about the css in it.

My last question was primarily about any customizations that, apparently, you don't have. When you get the messages with black background, try setting to view as plain text, as the black could be somewhere in the HTML. If so, there is no simple fix.

If i try plain text or simple HTML there is no black background. No simple fix but fix anyway ?

As it's recent and only with outlook user, i thought it was an update on the outlook side. But then others should have the problem...

One would need to see the HTML itself to assess what is happening. With use of dark backgrounds now popular, it may be a new 'feature' in Outlook? I just don't know. Have you asked any of them about the black background? Otherwise, I have no suggestions.