When adding a transition (Fupla) to a project, compiling is not possible anymore. Multi-defined symbol

The reason for the error message is not clear and there is no multi-defined symbol in the new transition.

Problem
When adding a new transition (with a "Wait time" FBox) to an existing project an error appears on build:

Assembling: praca.sfc

Error 41: praca.inc: Line 129: Multi-defined symbol: __stc_id_001B7_var_00

Reason
There is a problem in Fupla which leads to this problem

Solution
For PG5 1.4 a patch is available on request from pcdsupport.