I use SharePoint 2013. I built a custom InfoPath form with Workflow. It worked perfect until a few days ago when a problem emerged.
Every time I try to submit the form I get "Sending Data to the Server" message for about 15 minutes. The form gets submitted, but the workflow never starts.
I tried to republish the InfoPath form and the workflow, but it did not do any good. The rest of the forms I have are working fine, but I built them using SP 2010 platform.