This “Someone is currently logged into the APC Management Web Server. Please try again later” error happen if someone just closes the browser instead of logging off. In this case, APC web server thinks that the session is still running and they do not allow another session to be created existing session closed first. There are several ways to fix this problem:
1. Add logout.html after the URL
I read this from https://community.spiceworks.com/how_to/42177-someone-is-currently-logged-into-the-apc-management-web-server-error
If you are usually accessing from http://x.x.x.x then modified to http://x.x.x.x/logout.htm this will work fine as long as your computer IP address are the same as the last successful login computer. If this doesn’t work because you have different IP address then you have to find the last successful login IP address as described in this post and video.
2. Telnet the device and logoff
From http://forums.apc.com/thread/3263 you can use telnet programs such as PuTTY or terminal to log in to the device and log out. This work if you have telnet port open (port 23 or 22), if not you have to telnet directly to UPS serial port.
3. Using FTP this is my experience
This is only required if your IP address different from the last successful login user. If the same IP address uses no 1 above.
All our client computers are DHCP client means it sometimes got a different IP address from the server. If we forgot to log out after using APC web management server then the error Someone is currently logged into the APC Management Web Server will arise and we cannot just add logout.htm at the end of UPS address as in step no 1 because the IP address is different. Below are steps how we can overcome this problem.
This should work if FTP port opened and it does on my UPS.
Open file event.txt
Look for the IP address from last successful logged in.
Now login from a computer who have the same IP address but first you have to log out using http://x.x.x.x/logout.htm
After that, you should able to log in.
If you are still unsure how to do this, I made this video for you.
Summary of above video is:
Login to APC device FTP
Open event.txt file
Find the last successful login IP address
Change the IP address to be the same as in the event.txt record.
Logout by adding logout.htm after device’s IP address
Now you can login again
4. Press reset button on the network management card
If you have physical access to the UPS you can press the reset button on network management card. This card usually located on the rear panel of UPS. This is the most simple solution to the error message: Someone is currently logged into the APC Management Web Server. However, this method requires access to APC UPS physical device. Please see below picture to find the exact location of the button.
About APC management web server:
We use an APC management web server to check current UPS status, voltage, battery etc. The most important for us is to configure alert if the room temperatures go beyond the limit. It means something happens with an air conditioner that can cause servers down/broken because of overheat.
I configure the setting so that anytime temperature rise above the limit in the server room because of the problem with air conditioner, maintenance team and IT team are the ones who got alert and we try to fix before something bad happen with servers and other IT equipment in that room. This is a very important feature for us and we glad it worked perfectly. Oh yes by the way our APC UPS model is: SMART RT8000