The base unit of measure cannot be changed; choose "Display errors"

What causes this issue?

You wanted to change the base unit of measure. However, you can do so
only under certain circumstances, including the following:
If there are no stocks of the material in the current period and in the
previous period
If there are stocks in the previous period, you can clear them as
follows:
Post the stock in the previous period to the current period (for
example, using movement type 561) so that the stock for the previous
period is the same as the stock for the current period.
Clear the stock with the posting date in the previous period (for
example, using movement type 562).
If no purchase requisitions, purchase orders, or scheduling agreements
exist for the material

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?

Choose <LS>Display errors</> to see why you cannot change the base unit
of measure for this material.
The pushbutton <LS>Display errors</> appears only in dialog mode, not
in data transfer or in mass maintenance. If this message appears in
data transfer or in mass maintenance, and you want to know why the base
unit of measure cannot be changed, access the material in dialog mode
using the relevant transaction below, try to change the base unit of
measure as required, and then choose <LS>Display errors</>:
Industry
<DS:TRAN.MM02>Proceed</>
Retail
<DS:TRAN.MM42>Proceed</>

Error message extract from SAP system. Copyright SAP SE.