Ionic 3 app - finding the source of error

I have an Ionic (latest version) app with Ionic Pro error monitoring running on it. In the last days, I got a lot of errors like these:

Uncaught (in promise): 0 -  {"totalSize":0,"position":0,"total":0,"loaded":0,"lengthComputable":false,"cancelBubble":false,"returnValue":true,"srcElement":{"statusText":"","status":0,"response":"","responseType":"","responseXML":null,"responseText":"","upload":{"onprogress":null,"onloadstart":null,"onloadend":null,"onload":null,"onerror":null,"onabort":null},"withCredentials":false,"readyState":4,"timeout":0,"onreadystatechange":null,"ontimeout":null,"onprogress":null,"onloadstart":null,"onloadend":null,"onload":null,"onerror":null,"onabort":null,"__zone_symbol__loadfalse":[{"type":"eventTask","state":"scheduled","source":"XMLHttpRequest.addEventListener:load","zone":"angular","runCount":0}],"__zone_symbol__errorfalse":[{"type":"eventTask","state":"running","source":"XMLHttpRequest.addEventListener:error","zone":"angular","runCount":2}]},"defaultPrevented":false,"timeStamp":1524546205615,"cancelable":true,"bubbles":false,"eventPhase":2,"currentTarget":{"statusText":"","status":0,"response":"","responseType":"","responseXML":null,"responseText":"","upload":{"onprogress":null,"onloadstart":null,"onloadend":null,"onload":null,"onerror":null,"onabort":null},"withCredentials":false,"readyState":4,"timeout":0,"onreadystatechange":null,"ontimeout":null,"onprogress":null,"onloadstart":null,"onloadend":null,"onload":null,"onerror":null,"onabort":null,"__zone_symbol__loadfalse":[{"type":"eventTask","state":"scheduled","source":"XMLHttpRequest.addEventListener:load","zone":"angular","runCount":0}],"__zone_symbol__errorfalse":[{"type":"eventTask","state":"running","source":"XMLHttpRequest.addEventListener:error","zone":"angular","runCount":2}]},"target":{"statusText":"","status":0,"response":"","responseType":"","responseXML":null,"responseText":"","upload":{"onprogress":null,"onloadstart":null,"onloadend":null,"onload":null,"onerror":null,"onabort":null},"withCredentials":false,"readyState":4,"timeout":0,"onreadystatechange":null,"ontimeout":null,"onprogress":null,"onloadstart":null,"onloadend":null,"onload":null,"onerror":null,"onabort":null,"__zone_symbol__loadfalse":[{"type":"eventTask","state":"scheduled","source":"XMLHttpRequest.addEventListener:load","zone":"angular","runCount":0}],"__zone_symbol__errorfalse":[{"type":"eventTask","state":"running","source":"XMLHttpRequest.addEventListener:error","zone":"angular","runCount":2}]},"type":"error"}
at c (polyfills.js:3:19752)
at ? (polyfills.js:3:19174)
at ? (polyfills.js:3:21242)
at t.invoke (polyfills.js:3:14976)
at Object.zone._inner.zone._inner.fork.onInvoke (vendor.js:4982:33)
at t.invoke (polyfills.js:3:14916)
at r.run (polyfills.js:3:10143)
at ? (polyfills.js:3:20242)
at t.invokeTask (polyfills.js:3:15660)
at Object.zone._inner.zone._inner.fork.onInvokeTask (vendor.js:4973:33)

Is there any way to find the source of this errors? Is the problem in my code or is it just an Ionic/Angular bug?