An example of how to find out root cause of HTTP request failed in Fiori

Issue: When you try to create a new Opportunity in Fiori, you meet with the following error message in UI:

Click “Show Details” hyperlink:

Click F12 to open Chrome development tool, you could see more detail about this error. The exception has prefix “IWBEP” which indicates this exception occurred in the backend system.

Log on to backend system, set a breakpoint on CONSTRUCTOR of exception class /IWBEP/CX_MGW_BUSI_EXCEPTION, repeat the step in Fiori UI. The breakpoint is triggered as expected:

From the callstack in debugger we can know the incomplete customizing means the process type to be used in Fiori has not been configured in backend system yet: the error message is raised because lt_processtype is initial.

Then scroll up the code a little bit, and then we can find the context and reason why lt_processtype gets empty.