Getting 'HTTP 502.5 Process Failure' from time to time

I have self-contained application targeting .net 4.6.1 running on IIS 8.

From time to time we get the famous error HTTP 502.5 Process Failure and a couple of same logs in the Event Viewer with Failed to start process with commandline '".\<appname>.exe" ', ErrorCode = '0x80070002.

I have read and tried every post on the internet about that error and still have no idea why this happens.

Today I just restarted the IIS (after I added some binding) and when I opened the website I got it, after less then a minute everything was fine and couldn't reproduce it.

Additional info:

1. My web.config looks like:

<aspNetCore processPath=".\<app_name>.exe" arguments="" stdoutLogEnabled="true" stdoutLogFile=".\logs\stdout" forwardWindowsAuthToken="false" />

2. Found some warnings in the Event Viewer with the Maximum rapid fail count per minute of '10' exceeded. - no idea if this is related.

UPDATE:

I managed to reproduce this on our pre-prod environment. After I restart the IIS and try to open http://localhost I got the error from above - EVERY TIME. As soon as I hit the Application on http://localhost/ everything is working.