Are you using surfboard central app?

Is this happening when you are trying on different web browser?

Please try clearing browsing history and login.

Hello,

Thank you for responding.  I had tried Chrome, Edge, and Safari.  All failed with the same error message.  I cleared the browsing history on all three, and again tried all three with no success.  I do not use the Surfboard central app.

I had also tried, unplugging, disconnecting cable, and disconnecting Ethernet.  I then connected cable, connected power,,and connected Ethernet.  Ethernet and wifi all fine, but same error message trying to log in..   again, everything was working perfect for the first two weeks I owned it, and then this.  
 

I really am hesitant to do a hard reset.  If the same problem persist after a hard reset,  I’ll have no ability to set up Ethernet or Wi-Fi settings.

Since you unable to access the GUI web portal with all the possible troubleshooting steps, I suggest you to perform factory reset the modem. Moreover, if you are performing factory reset on the modem, all the customized settings will be changed to default settings.

To perform factory reset, find the link given below:

http://arris.force.com/consumers/articles/General_FAQs/G34-G36-Factory-Reset

After performing factory reset, try to access the GUI web portal again by connecting default Wi-Fi network on your devices.

Thank you again,

somewhere I saw, read, etc that a hard reset still  keeps the old password?  If it does, that is not a problem?  I know all my setting, so aside from the time, no problem.  But if the device become unusable, well, now I have no connectivity, eg , etc , etc,…

As you mentioned no connectivity, let us know whether you have internet access on the modem.

If there is no internet, find the link to proceed with troubleshooting steps:

http://arris.force.com/consumers/articles/General_FAQs/G34-G36-Troubleshooting-Internet-Connection

Hello,

I have both ethernet and Wi-Fi.  I can get to the opening login screen of the G34.  There are green checked circles for internet, Ethernet, Wi-Fi, and medium security.  The username shows admin, which I never changed.  And the password box is empty.  When I type in my password, that is when the error message “Can not get password for admin from backend!” pops up.   I had been able to log in with my password for the two prior weeks I had the modem,  the modem was purchased new from arris website.

If you are unable to access the GUI web portal, Make sure that there in no VPN enabled in your device.

Also try to access without co-axial cable on modem.

Thank you.  Hard reset worked .