Windows 10 / Cisco WebEx – Invalid input or system error. Please try again or contact your site administrator’

Recently when trying to run Cisco WebEx and join a Live Meeting on Microsoft Windows 10, I received the following error message:

Invalid input or system error. Please try again or contact your site administrator

In order to provide a workaround to the issue, I was required to run Internet Explorer 11 in Developer Mode [F12] and use document mode ‘9’ and user agent string ‘Internet Explorer 9’ in emulation, to which I was able to run Cisco WebEx and join the Live Meeting.

The cause of the issue appears to be due to the parsing of the user agent string and should be resolved in T30.1 which will fully support the Microsoft Windows 10 operating system, whilst T29.13.40 provides partial support.