Activity Chart Checks : (C4020) Arrows not a component of any compound data-flow

(C4020) Arrows not a component of any compound data-flow

Error In:
Completeness
Description:
This test is pointing out flow-lines in activity charts which are not recognized as valid flow-lines, and in some cases might cause other Check Model errors like C4058 and C4059.
Erroneous Elements:
Flow Lines