000388 : <value> will lose Zs, since the output is not Z enabled

Description

When appending input features containing z-values to a target feature class that is not enabled to store z-values, the input z-values will be lost.

Solution

If you want to preserve z-values, make a copy of the inputs beforehand. Alternatively, make a copy of the target dataset, ensuring that the Output Has Z values environment setting is set to Enabled.