Json parse error when calling stopInstance

[janniclas]

Describe the bug
Upon calling stopInstance via the docker control inside the table component a json parse error is raised.

Object { headers: {…}, status: 200, statusText: "OK", url: "http://localhost:8083/api/stopInstance?instanceID=1", ok: false, name: "HttpErrorResponse", message: "Http failure during parsing for http://localhost:8083/api/stopInstance?instanceID=1", error: {…} }

{…}
​
error: {…}
​​
error: SyntaxError: "JSON.parse: unexpected character at line 1 column 1 of the JSON data"
	onLoad http://localhost:8083/vendor.js:32409:46
	invokeTask http://localhost:8083/polyfills.js:2766:17
	onInvokeTask http://localhost:8083/vendor.js:76418:24
	invokeTask http://localhost:8083/polyfills.js:2765:17
	runTask http://localhost:8083/polyfills.js:2533:28
	invokeTask http://localhost:8083/polyfills.js:2841:24
	invokeTask http://localhost:8083/polyfills.js:3885:9
	globalZoneAwareCallback http://localhost:8083/polyfills.js:3911:17
​​
text: "Operation accepted."
​​
<prototype>: Object { … }
​
headers: Object { normalizedNames: Map(0), lazyUpdate: null, lazyInit: lazyInit()
 }
​
message: "Http failure during parsing for http://localhost:8083/api/pauseInstance?instanceID=1"
​
name: "HttpErrorResponse"
​
ok: false
​
status: 200
​
statusText: "OK"
​
url: "http://localhost:8083/api/pauseInstance?instanceID=1"
​
<prototype>: Object { constructor: HttpErrorResponse()
 }