Make sure the updates fixed issue : Go to the Firefox 3 Bar Menu --> Help ? --> Troubleshooting Information Page and take a look in the Accessibility section if accessibility is set to "true" there. if yes, go to the Firefox 3 Bar Menu --> Options --> Privacy & Security panel and under Permissions check the setting to Prevent Accessibility Services from accessing your browser. Restart Firefox

if is fixed then  : You could try this please : Go the Menu then Tools --> Options --> Performance and untick everything. change the recommended size lower then see how it runs. Note: 0 = No Multi-proccesor = slow again. TRY 2 Restart Firefox after making these changes please.

Please let us know if this solved your issue or if need further assistance.

The box to prevent accessibility services from accessing your browser is unchecked. Is that what it should be? The settings indicate:

Accessibility Instantiator UNKNOWN|C:\Program Files (x86)\Siber Systems\AI RoboForm\robotaskbaricon.exe

Espressolover said

The box to prevent accessibility services from accessing your browser is unchecked. Is that what it should be? The settings indicate: Accessibility Instantiator UNKNOWN|C:\Program Files (x86)\Siber Systems\AI RoboForm\robotaskbaricon.exe

Yes to not checked.

No idea about 2nd one as it is not a part of Firefox. It is a separate program and is a password manager. Make sure it is updated and is compatible with Firefox 57+

If still have issues follow directions of 1st post , 2nd part.

Please let us know if this solved your issue or if need further assistance.