I'm using Idle Master Extended v1.10.0
still working and working good.
https://files.catbox.moe/edwkd6.png

Login issue was fixed in the newest version of Idle Master Extended (v1.8)
please update first and see if it works before you continue this post.
https://github.com/JonasNilson/idle_master_extended/releases/

this still works for Idle Master Extended, which will solve:

• Login window just disappears after submit (can't login)
  
• Always shows Idle Complete (actually session error)

try it if you got same problem.

Idle Master Extended by JonasNilson[github.com]
which fixed the previous glitch due to web steam update, download it before you proceed.

please reply if it works for you, and which will also bump the thread that will help more people.


Remove ANY file or folder which was for storing login data that are located here:
C:\Users\"USER NAME"\AppData\Local\IdleMaster
sometimes it will cause IM won't start new login session

For Chrome[chrome.google.com]
For Firefox[addons.mozilla.org]
For Opera[addons.opera.com]

Install it and login to web steam with your browser,
after you logged-in,
press Cookie Editor button,
you should see something like this:
https://i.imgur.com/2dcaPWq.png

What we need here is "sessionid" and "steamLoginSecure",

now open IM settings and click the "Lock" icon in the left corner,
press the "Eye" button,
paste the text you got from Cookie Editor,
if your steam has parental protect enabled, paste the text in too,
when you done it should look like this:
https://i.imgur.com/ixtJmDf.png

Press the Update button,
and IGNORE the not valid message https://i.imgur.com/xmOArBN.png
close settings window,
your IM should now works fine,
and the problem shouldn't bother you in a while until login session expired
https://i.imgur.com/XOkzjfu.png


-LaZycAt