Most of the time my Visualforce page with embedded Lightning components (via Lightning-Out in Visualforce) work fine. However, intermittently the lightning components fail to appear and the quoted error above shows up in the footer of the page.

I'm wondering if this is a browser/desktop performance issue causing mis-timing of DOM manipulation, or something else.

Anyone got any ideas?

SELECT AssigneeId,Id,PermissionSet.Name FROM PermissionSetAssignment WHERE AssigneeId = '< id >' AND PermissionSetId = '< id >'

On firing above query using API (/services/data/v20.0/), i am getting error mentioned below:
 

Array(
   [message] => sObject type 'PermissionSetAssignment' is not supported
   [errorCode] => INVALID_TYPE
)

 

I noticed that my Lightning Out App in classic SF is no longer working and the console shows a parsing error.

myVF:504 Uncaught SyntaxError: Unexpected token u in JSON at position 14660

I tried reverting to a version that worked from 3 weeks ago, but it seems to still not work..
Here is my VF code.
myVF.page

<apex:page sidebar="false">
<apex:includeLightning />
    <div id="myDivId">
    </div>
    
    <script>
        var myUserContext = "{!$User.UITheme}";
        $Lightning.use("c:LEXComp", function() {
        $Lightning.createComponent(
            "c:LEXContainer",
            {},
            "myDivId",
            function(cmp) {
                console.log('component created');
                console.log(cmp);
            });
        });
     </script>
</apex:page>

The lightning component works fine separately and within the LEX environment, this seems to only be an issue with Lightning Out.