Characters cannot be displayed in the requested code page.

What causes this issue?

Conversion is not possible. The data has been read as far as is
possible. Text data, for which the conversion failed,
is undefined.
Characters cannot be displayed in the requested code page.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.