Follow-up/replacement material relationship has cycles

What causes this issue?

You defined list field <LS>Check for Cycles</> in the current follow-up
type such that the system runs a check for two-level cycles when a
follow-up/replacement material relationship is created.
A two-level cycle exists when the follow-up/replacement material of a
follow-up/replacement material relationship is the original material in
a second follow-up/replacement material relationship, and the
follow-up/replacement material in this second follow-up/replacement
material relationship is the original material of the first. In
addition, both relationships have to have the same follow-up type
number.
Example A
Follow-up/repl. mat. rel. 1,,Original material:,,,,1000
,,Follow-up/repl. mat.:,,,,2000
,,Follow-up type no.:,,,,01
Follow-up/repl. mat. rel. 2,,Original material:,,,,2000
,,Follow-up/repl. mat.:,,,,1000
,,Follow-up type no.:,,,,01
-> Two-level cycle
Example B
Follow-up/repl. mat. rel. 1,,Original material:,,,,1000
,,Follow-up/repl. mat.:,,,,2000
,,Follow-up type no.:,,,,01
Follow-up/repl. mat. rel. 2,,Original material:,,,,2000
,,Follow-up/repl. mat.:,,,,1000
,,Follow-up type no.:,,,,02
-> Not a two-level cycle
Example C
Follow-up/repl. mat. rel. 1,,Original material:,,,,1000
,,Follow-up/repl. mat.:,,,,2000
,,Follow-up type no.: ,,,,01
Follow-up/repl. mat. rel. 2,,Original material:,,,,2000
,,Follow-up/repl. mat.:,,,,3000
,,Follow-up type no.:,,,,01
-> Not a two-level cycle
You defined in Customizing that the system should display a warning
message or error message when a two-level cycle exists.

System Response

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

How to fix this error?

If the system displays a warning message, you can leave the
follow-up/relationship material relationship unchanged. The system saves
the relationship.
If the system displays an error message, you have to change the original
material and/or the follow-up/replacement material. The system does not
save the relationship.
Alternatively, you can also create the follow-up/replacement material
relationship for a different follow-up type number.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.