Group & contains overlapping values

What causes this issue?

Object (&V1&: &V2&) contains overlaps. This is not allowed. Each single
value may occur only once. Intervals must not overlap.
The first determined area of overlap is: &V3& &V4&.

System Response

The function is not executed.

How to fix this error?

If you still want to use &V1&, you first have to remove all overlaps:
Open another window
In this window, carry out the unambiguity check for &V1&
Remove the determined overlaps

Error message extract from SAP system. Copyright SAP SE.