When using a browser, connect toPE6208AV/6108AV/8208AV can not login the error message is Login fail.  

To solve this issue, please use the WEB browser (Firefox Portable V.107.0) attached with this FAQ to upgrade PE6208AV/6108AV/8208AV firmware to  V1.3.122  or later.

You can also download for below web site:

https://sourceforge.net/projects/portableapps/files/Mozilla%20Firefox%2C%20Portable%20Ed./Mozilla%20Firefox%2C%20Portable%20Edition%20107.0/

To upgrade the firmware, please download the firmware and manual from 

https://www.aten.com/global/en/supportcenter/downloads/?q=PE6208AV

Please check the manual for how to upgrade firmware. 

If you still have problems, please contact ATEN Tech Support

https://eservice.aten.com/eServiceCx/Common/FAQ/askQuestion.do?type=None