It is a static error if the expanded QName and number of arguments in a function call do not match the name and arity of a function signature in the static context. Error while evaluating expression: $currentResource/concat(/god/@id). concat() requires at least two arguments Invalid value for cast/constructor. Error while evaluating expression: $currentResource/xs:integer('STRING'). can not convert 'STRING' to xs:integer exerr:ERROR Error while evaluating expression: $currentResource/god/name/english[@]. org.exist.xquery.XPathException: err:XPST0003 unexpected token: ] [at line 1, column 36] [at line 265, column 23]. Error while evaluating expression: $currentResource/god/name/english[@]. org.exist.xquery.XPathException: err:XPST0003 unexpected token: ] [at line 1, column 36]