Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

Blinking vertical lines in tab bar?

  • 3 replies
  • 35 have this problem
  • 3 views
  • Last reply by M.G.

M.G.
M.G.
more options

There are small vertical lines in the tab bar. They appear after closing tabs. They blink and change places when I hover the cursor over any Firefox buttons or bars. And sometimes they start to blink and mirror the text cursor in the address bar.

Disabling all add-ons and themes does not affect them.

I'll try to add a screenshot of the problem.

There are small vertical lines in the tab bar. They appear after closing tabs. They blink and change places when I hover the cursor over any Firefox buttons or bars. And sometimes they start to blink and mirror the text cursor in the address bar. Disabling all add-ons and themes does not affect them. I'll try to add a screenshot of the problem.

Chosen solution

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

  • Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
  • Do NOT click the Reset button on the Safe Mode start window
Read this answer in context 👍 3

All Replies (3)

M.G.
M.G. Question owner
more options

Here is a screenshot

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

Chosen Solution

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

  • Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
  • Do NOT click the Reset button on the Safe Mode start window
M.G.
M.G. Question owner
more options

It was the hardware acceleration.

Thank you cor-el!