Process Model- Appian Step-By-Step Exercise 10

I am getting this below error, while debugging Request Maintenance process model

ERROR An error occurred while evaluating expression: =localize("de","","fr_CA","","ru","","sv","","pt","","ko","","el","","fr_CH","","it","","fr_FR","","iw","","es","","ar","","zh_HK","","en_GB","","th","","en_US",tostring("Request Maintenance for Vehicle: "pv!maintenance['recordType!{b5aaf6ce-8d6c-4517-b332-68ba3a0c3655}W003SA Maintenance.relationships.{6b611f24-010d-41e4-a738-f889ab7c2bea}vehicle.fields.{fc426423-e013-40d4-b3a3-505e88858e0d}vin']),"ja","","es_MX","","zh_CN","","pl","","tr","","nl","") (Expression evaluation error at function 'tostring' parameter 2: Invalid symbol found (open_bracket))

below is the variable expression