Sorry for any inconvenience caused by this issue. We understand your frustration. In most cases, the keyboard language is set by your operating system. Therefore, it is a good idea to check that your operating system's language settings are configured correctly. For more information on setting your language in Windows 10, please refer to this Microsoft support article: *[http://windows.microsoft.com/en-ca/windows-10/how-to-add-an-input-language-to-your-pc#v1h=tab01 How to add an input language to your PC] However, if your keyboard layout is correctly configured, but the issue is still occurring, please try Firefox safe mode. Safe mode is a diagnostic mode that will temporarily disable your addons, disable hardware acceleration and reset some Firefox settings. If the issue doesn't occur in safe mode, the first step would be to ensure that none of your addons are causing the issue. If the issue still occurs in safe mode, please let us know. For more information on using Firefox safe mode, please refer to this Mozilla support article: *[[Troubleshoot Firefox issues using Safe Mode]]