K2 Workflow API - Swagger UI is not working and you cannot access API Calls (Operations, ServerEvent, Task and etc.)
Example of a working K2 Workflow API:
It was discovered the 'X-UA-Compatible' value to IE=EmulateIE7 is incorrect:
To resolve this issue, change the header 'X-UA-Compatible' value to IE=EmulateIE11 in IIS Manager.
Please note: An IISRESET is required.