Firefox having issues with ghost "Ctrl" key
Firefox sometimes seems to recognise "Ctrl" key as pressed while typing. As well when trying to use keyboard shortcuts they are not working since the Firefox seems to have the "Ctrl" key input as "Yes". Basically the browser works and reacts as "Ctrl" key is jammed / stuck. Tried with several keyboards, tried re-installing the browser, updated Firefox as well.
Opaite Mbohovái (4)
Try to press the Ctrl key and possibly the other modifier keys (Shift and Alt) a few times if they appear stuck.
Firefox may have missed a key release for some reason.
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 or otherwise make changes.
Pressing the key sometimes helpes, 2-3 times usually do the trick but the issue can re-appear in a several moments / minutes. Other modifier keys work fine. Safe mode does not help - got stuck after 2 minutes of usage.
If the Firefox Safe mode doesn't help then you probably have other software running in Windows that 'eats' the Ctrl key press or otherwise prevents Firefox from seeing it.
Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.
You can inspect the startup programs with the Autoruns utility.
The only program that may be interfering with Firefox is programmable software for Saitek but I booted the PC without it and as well tried on a different keyboard - doesn't help at all. Windows does not eat the key as well as I tried different programs - the issue appears only in Firefox.