Hello ,

Please do the following :

Click the orange Firefox button > Click the options > Select options from the dropbox > Click content tab > Choose the default font and the size > Click ok.

Report if that helps ! Thanks!

Try to disable hardware acceleration in Firefox.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

what are the defaults? there is no option to set a default. the following are my settings: Fonts: Western Proportional: Serif, Size: 16 Serif: Times New Roman Sans-Serif: Arial Monospace: Courier New, Size: 12

  Minimum Font Size: none

NOTE: these last 2 parameters have no effect no matter what the value.

so far so good.