Summary
When starting a business process from Web Access, you may receive the following error message:
The remote server returned an error: (417) Expectation failed.
Workaround
This issue can occur when there is an improperly configured proxy intercepting traffic between the Web Access server and the Workflow server. Make sure that the Web Access server can properly communicate with the Workflow server. Try disabling the proxy to test if you can start business processes from Web Access.