Issue
After doing a migration of the K2 server and SQL server to Azure, when attempting to start a workflow from a Form using the Start a Workflow action, an instance of the workflow does not get created.
When you capture a network trace from your browser Developer Tools, you may see a http 403 error on one of the AjaxCall.ashx requests. If you click on the Preview tab, there is a message saying “Sorry, you have been blocked. You are unable to access <domain name>" and at the bottom of the page, you will see this:
Resolution
This is coming from the Cloudflare web application firewall (WAF). The Ajaxcall.ashx request is blocked because it triggered the WAF rule listed in the event. Please check with your infra/network team to perhaps disable the rule or create a rule for the IP/URL in question to bypass this in Cloudfare so that the request is allowed.