&1 &2: Start constraint conflicts with fixed finish

What causes this issue?

The fixed finish date of the project element is before its fixed start
date.

System Response

The system sets the duration of the project element to zero. The system
may calculate the dates incorrectly, for example,
if there are no actual start or finish dates.

How to fix this error?

Correct the fixed start date or the fixed finish date.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.