Problem
Opening a workflow from K2 Designer takes around 2 minutes to complete while closing the same workflow would take over 7 minutes.
Solution
This issue may be isolated to the browser used and not necessarily the size and complexity of the workflow in question. You may try clearing the browser storage and cache first to improve the overall duration:
1. Open K2 Designer on your browser.2. Open the Developer Tools then go to the Application tab.3. Select 'Storage' then click on 'Clear Site Data'.4. Clear the browser cache as well.5. Close the browser.6. Perform an IISRESET on the web server.