&1 &2: Start constraint conflicts with a predecessor's date

What causes this issue?

A constraint is set for the start of the project element.
During forward scheduling for the project element, the system calculates
a start date from the predecessor relationships. The system compares the
determined start date (earliest start) with the constraint for the start
date. The warning appears if the start date conflicts with the
constraint for the start date.

System Response

The system ignores the predecessor relationship and sets the fixed start
date of the project element as the calculated start.

How to fix this error?

Check whether the fixed start date is realistic.

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.