Activity Chart Checks : (C4021) Flow-lines with incomplete source definition

(C4021) Flow-lines with incomplete source definition

Error In:
Completeness
Description:
There are flow-lines whose source is not connected to an activity, data-store, or connector. The source of such flow-lines appears in the activity chart as a small line perpendicular to the flow-line.
Erroneous Elements:
Flow-lines
Example: