You are not authorized to process a blocking reason

What causes this issue?

The message means either:
You selected "Select blocking reasons" on the invoice release initial
screen, or
You selected the function "Delete blocking reason" in the invoice list.

How to fix this error?

On the initial screen:
You are only authorized to release invoices which do not have any
blocking reasons. Therefore, select in the area "Blocking reasons" the
field "All blocking reasons".

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

In the list:
You are only authorized to release invoices which do not have any
blocking reasons.
To obtain an authorization, contact your system administrator.

Error message extract from SAP system. Copyright SAP SE.