I have the same issue. I get asked for extension and password but time out. This happens with IE, Firefox & Chome.
pgrep FOP2 returns 3328. I assume that is a PID?
Even though I am accessing internally, I forwarded port 4445 just in case.
I am running 2.25 and Elastix 2.20-25
I disabled FOP and made sure it does not load at boot up. Flash Operator Panel screen is blank.

I've tried logging in with different extensions, reloading asterisk, rebooting, all no help.

Any ideas?

Thanks