Where is that cookies.txt file?! That might be your Windows/Internet Explorer cookies file.

Firefox stores its cookies in a database file named cookies.sqlite in your currently active Firefox profile folder. The easiest way to open that folder is using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button. This will launch a new window showing your Firefox settings. Please don't delete any files while Firefox is running, and be cautious if you do delete anything that you know exactly what it is and what will happen if you delete it. Feel free to ask questions about that.

it was in my Profile folder

there is a cookies.txt and cookies.sqlite

Does the cookies.txt file have an ancient modification date? Firefox hasn't used cookies.txt for many, many versions now and I think you probably can just delete it (or to be conservative, rename it to cookies.old).

Hmm, I discovered there are some add-ons that export your Firefox cookies to a cookies.txt file. Do you maybe have one of those running? You can check on the Add-ons page. Either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Extensions.

I have a cookie Manger add-on

Which one is it, specifically? If you check its Options, could it be creating the file? Often you can find an Options button for an individual extension on the Add-ons page.

unfortunately there isn't Is it safe to just delete it "cookies.txt"

You can delete or move this cookies.txt file elsewhere to see if that works or that a new file gets created.

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

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/

thank a lot for your help guys