V1910-48G switch web management GU misbehaves after upgrading to 5.20.R1518P01 FW using Web mgmt

[n3mmr]

I updated my R1111 software to R1518P01, using the web mgmt GUI, device->device maintenance.

after the reboot the web mgmt GUI misbehaves ridiculously,.

If I log in, click Device, and then click on Device Management or System Time or almost any other choice, I don't reach the menu choice but instead the Web User Login panel appears, sometimes with some style document errors like the user name and password being slightly displaced relative to the panel.

If I keep logging in on the login panels as they appear, eventually I will get an error message

"The number of login users has reached the maximum!" and then I must wait for a web timeout on the switch to try again

The switch SEEMS to work as a switch, but this is very unsatisfactory.

All of my switches are now HW rev.B, Bootrom v 178, 3Com Baseline Switch 2952-SFP Plus Software Version Release 1518P01

One of them has serial no 927FDFS4591FD

[n3mmr]

As an aside:

The reason for the upgrade frenzy was supposedly rational: we had had trouble setting up NTP timekeeping on the switches, so we started assuming that could be fixed in later FW.

[n3mmr]

The subject line should of course say "V1910-48G switch web management GUI misbehaves..."