How To Fix UPC_FW121 - Several planning packages available, executing level &1 not possible

SAP Error Message - Details

• Message type: E = Error

• Message class: UPC_FW - Messages for Planning Framework, Areas, Levels and Packages

• Message number: 121

• Message text: Several planning packages available, executing level &1 not possible

What causes this issue?

When a planning level contains more than one package, then the direct
execution of the first planning layout of the level is not possible,
since the system cannot determine which package should be used for the
data to be processed.

How to fix this error?

Proceed in one of the following ways in order to start a planning
layout by simply clicking on it:
Click on the desired planning package. The first layout of the planning
level is executed.
Edit the level or the set planning profile so that no packages are
contained in it. In this case, simply by clicking on the planning
level, the first layout in it is executed.

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.