Hey. I am looking for a help on message "Protocol Negotiation failed - Please try again" I don't know since when but TeamViewer on all the computers at our office show "Protocol Negotiation failed" when they act as a remote device, while control devices show "Ready to connect (secure connection)" but nothing happens. I have done the following - update TeamViewer on both remote and control sides. - uninstall and reinstall TeamViewer - check and unable firewall setting on both remote and control sides. - reboot network rooter at our office - reboot devices on both remote and control sides We have a mix of OSs: Windows 10 Pro and iOS. The version of TeamViewer we're currently using is 13.2.26558 (Windows 10) and 13.2.26559 (iOS). Could anybody give me any suggestion or tell me what I can do, please? Thank you very much in advance.
... View more