obj needs to be an object

{ AssertionError [ERR_ASSERTION]: obj needs to be an object
at JSONPath.nodes (/var/task/node_modules/jsonpath/lib/index.js:113:10)
at allNodes (/var/task/node_modules/dynamo-update-expression/lib/dynamo-update-expression.js:404:15)
at diff (/var/task/node_modules/dynamo-update-expression/lib/dynamo-update-expression.js:347:25)
at partitionedDiff (/var/task/node_modules/dynamo-update-expression/lib/dynamo-update-expression.js:318:18)
at Object.getUpdateExpression (/var/task/node_modules/dynamo-update-expression/lib/dynamo-update-expression.js:162:28)
at PlaceModel.update (/var/task/node_modules/dynamodb-loader-model/src/classes/model.js:221:38)
at <anonymous>
at process._tickDomainCallback (internal/process/next_tick.js:228:7)
generatedMessage: false,
name: 'AssertionError [ERR_ASSERTION]',
code: 'ERR_ASSERTION',
actual: false,
expected: true,
operator: '==' }