No search fields defined for this line layout

For the selected line layout, the system configuration settings do
not contain any specifications concerning the fields for which a search
is to be carried out.

How to fix this error?

You may want to choose a line layout that permits you to search (if so,
choose <LS>Settings</> --> <LS>Line layout</>).
If you want to perform a search for the set line layout, you must ask
your system administrator to change the display variant in the
Customizing system of Invoice Verification. For the line layout, you
can enter the fields that are to be offered as search criteria (via
<LS>Environment</> --> <LS>Field selection</> --> <LS>Search</>).

Error message extract from SAP system. Copyright SAP SE.