Manually-entered quantity in & is outside the error range tolerance(high)

What causes this issue?

You have manually entered a quantity, but that value is higher than the
value calculated by the system. All manual entries are checked by the
system to determine if they are different than the system calculations.
The difference between the two values (which is specified as a
percentage) is larger than the tolerance percentage defined in the
conversion group.

How to fix this error?

Change the manually-entered quantity so that it is within the accepted
tolerance ranges, or increase the percentages for the tolerance check in
the conversion group (Transaction O588).
,,<ZH>Note</>: If you do not have the authorization to do this, contact
your system administrator.
Sample ranges: Examples:
High error range 10% 1100.00 and greater
High warning range 5% 1050.00 - 1099.99
No message sent 1000.01 - 1049.99
System-calculated value 1000.00
No message sent 999.99 - 950.01
Low warning range 5% 950.00 - 900.01
Low error range 10% 900.00 and less

Error message extract from SAP system. Copyright SAP SE.