EX 2013 ecp/?ExchClientVer=15 error 400

Hi,

I'm trying to solve this problem for a while now, everything still works with powershell.

When i try to open the Administrator part of ecp (localhost/ecp/?ExchClientVer=15) i get error 400. Owa and ecp-owa aren't a problem.  The event log is at the bottom.

I tried everything i could find on Technet/Google, rebuilding owa/ecp, installing cu update, etc

I'm trying to post get-ecp/owavirtualdirectory but fail b/c account is not verified yet.

I made a pastebin with the output of get-ecp/owavirtualdirectory & Event log:

past bin

. com /

grwpSR1c