Encountering the same troublesome issue, I found that it occurs specifically at line 1472 within ng-inspector.js where JSON.parse(eventData); is invoked.
Seemingly, the culprit lies in event.data containing a peculiar string starting with the letter 'M' - "Meteor._setImmediate.0.5014774943701923.5"
The following are the five lines preceding the JSON.parse() call in ng-inspector.js:
window.addEventListener('message', function (event) {
// Ensure the message was sent by this origin
if (event.origin !== window.location.origin) return;
var eventData = event.data;
if (!eventData || typeof eventData !== 'string') return;
eventData = JSON.parse(eventData);
Upon inspecting the event object in the debugger, the data property reveals:
event = MessageEvent {data: "Meteor._setImmediate.0.5014774943701923.5", origin: "http://localhost:3000", lastEventId: "", source: Window, ports:
Since ng-inspector.js functions as an Angular extension for Chrome, opting to uninstall it after transitioning to Meteor should resolve the issue.
An affirmation from another user confirms the remedy involves removing the Angular inspector Chrome extension, effectively resolving the problem.