Try to disable hardware acceleration in Firefox (you need to close and restart Firefox). Tools &gt;

Try to disable hardware acceleration in Firefox (you need to close and restart Firefox).

Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"

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

In Firefox Safe mode these changes are effective:

all extensions are disabled (about:addons)

default theme is used (no persona)

userChrome.css and userContent.css are ignored (chrome folder)

default toolbar layout is used (file: localstore-safe.rdf)

Javascript JIT compilers are disabled (prefs: javascript.options.*jit)

hardware acceleration is disabled (Options > Advanced > General)

plugins are not affected

preferences are not affected