Hi,
I did the upgrading to latest FW 7.01.4 without having WebUI login issue with the same credential. Could you please provide the following information:
1. What was the error when you failed to login the router after upgrading? Can you please provide screen shot if possible?
2. Have you tried to use different browser to login?
3. Can you login the device by SSH? Can you successfully ping the gateway?
4. How did you update the firmware? From local, server or RMS?
5. What was the RUT955 firmware version before upgrading?
6. Was there any error during upgrading process you've noticed?
Regards,
Ledong