An error has occurred

/db/apps/VNS/VNS_site/xquery/DALF.xq exerr:ERROR Error while evaluating expression: facets:get-facet("FT"). The actual return type does not match the sequence type declared in the function's signature: facets:facet-lookup(element()*, element()*, xs:string?) element(). Expected cardinality: exactly one, got 0. [at line 85, column 10, source: /db/apps/VNS/VNS_site/xquery/modules/facets.xq] In function: facets:facet-lookup(element()*, element()*, xs:string?) [172:10:/db/apps/VNS/VNS_site/xquery/modules/facets.xq] facets:get-facet(xs:string?) [1:1:/db/apps/VNS/VNS_site/xquery/modules/facets.xq] local:main() [90:14:/db/apps/VNS/VNS_site/xquery/DALF.xq]

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