Resolved Server Error 502 Bad Gateway accessing admin

[nas]

Hello,

Iam totally new to Plesk Onyx, the version iam using is 17.5.3 two days back iam started using the panel the last two days it was working fine expect the after I log in today and done some changes to hosting plans and I Press update all. Iam totally familiar with cpanel and because of the charges and other reasons I have planned to migrate to Plesk. today after doing above Iam not able to access the admin panel. The licence version iam using is Web host I don't know what I have done wrong if some one can help me it was so helpful. The screenshot of the error while Iam log to admin was attached in this post so please help me..

Other Details:

OS

Virtualization: kvm
Operating System: CentOS Linux 7 (Core)
CPE OS Name: cpe:/o:centos:centos:7
Kernel: Linux 3.10.0-514.el7.x86_64
Architecture: x86-64


Product version: Plesk Onyx 17.5.3 Update #20
Update date: 2017/08/29 07:32
Build date: 2017/03/17 16:00
OS version: CentOS 7.3.1611
Revision: 55d1b49a272f44666e1920eca8b6e4da449a38cd
Architecture: 64-bit
Wrapper version: 1.2

 

[nas]

Hello,

My problem was resolved automatically.. I thing it was an mistake happen in my end I mean I have made some changes in the Sessions Management
today I found an app In google play store offered by plesk to manage our server through plesk. So I have tried to access my plesk panel through browser
and again I got the same 502 error So I tried to access it through the app. It was working fine and When I came office the same system shows the 502 error
was able to access the plesk panel. So I gone to tools and settings and Sessions Management -> settings I can see the Session idle time was showing as 30 mIn
Wen I click on the Reset to default button it was changed as 300 Min so I thing may be it was happen because of this change