After using "Set a data value" my node title is deleted

Please help,

When i set a data value with a rule the title of that specific node is gone...

I just want to set the specific boolean field to another value.

Nielsvoo

Below the export of the rule

{ "rules_set_veld_open_voor_sollicitaties_op_nee_als_de_vacature_is" : {
    "LABEL" : "Set veld \u0022open voor sollicitaties\u0022 op \u0022nee\u0022als de vacature is verlopen",
    "PLUGIN" : "reaction rule",
    "WEIGHT" : "-1",
    "ACTIVE" : false,
    "TAGS" : [ "vacatures" ],
    "REQUIRES" : [ "rules" ],
    "ON" : [ "node_view" ],
    "IF" : [
      { "node_is_of_type" : {
          "node" : [ "node" ],
          "type" : { "value" : { "vacatures" : "vacatures" } }
        }
      },
      { "AND" : [
          { "data_is" : {
              "data" : [ "node:field-einddatum-vacature" ],
              "op" : "\u003C",
              "value" : [ "site:current-date" ]
            }
          },
          { "NOT data_is" : {
              "data" : [ "node:field-open-voor-nieuwe-sollicita" ],
              "op" : "IN",
              "value" : { "value" : { "9" : "9" } }
            }
          }
        ]
      }
    ],
    "DO" : [
      { "data_set" : { "data" : [ "node:field-open-voor-nieuwe-sollicita" ], "value" : "9" } }
    ]
  }
}