error "Syntax error" in Buffering with Geometry service

[AmmarAssem1]

Hello,

I am trying to using tool Buffer in Geometry service and using the result geometry to query filter but error occur when execute
querytask "SyntaxError: Syntax error
at fromJson (http://serverapi.arcgisonline.com/jsapi/arcgis/3.4/:15:143428)
at json (http://serverapi.arcgisonline.com/jsapi/arcgis/3.4/:15:116384)
at _49c (http://serverapi.arcgisonline.com/jsapi/arcgis/3.4/:15:119042)
at _1e1 (http://serverapi.arcgisonline.com/jsapi/arcgis/3.4/:15:42227)
at _1df (http://serverapi.arcgisonline.com/jsapi/arcgis/3.4/:15:41928)
at callback (http://serverapi.arcgisonline.com/jsapi/arcgis/3.4/:15:42749)
at Anonymous function (http://serverapi.arcgisonline.com/jsapi/arcgis/3.4/:15:121119)
at _4c2 (http://serverapi.arcgisonline.com/jsapi/arcgis/3.4/:15:123685)
at _4bc (http://serverapi.arcgisonline.com/jsapi/arcgis/3.4/:15:123558)
at resolve (http://serverapi.arcgisonline.com/jsapi/arcgis/3.4/:15:125019)"

Thanks,
Best wishes