I am posting this, to maybe save someones time, because I did not find a solution to this problem on K2 Community or Google.
Problem: When starting a workflow with the option Item added nothing happens, workflow doesn't start. No error in K2 logs.
Resolution: After thoroughly checking the sharepoint logs, I found an error in calling K2 event service, no endpoint, CRLF error. If site is created with default language choosing our native language (non-english) K2 SharePoint app can't send events to K2. Creating SP site with english as default language and adding our language as additional language solves the problem.
KEYWORDS: k2, event service, calling, endpoint, CRLF, language, sharepoint 2013, app, 4.6.11
This is a perfect example of what the community is for - thank-you for being a leader.
I've created simple workflow ( move the doc to another folder ) in SP 2016 but workflow didn't start on item added but works if I start manually,, please help .