Unable to load Admin index.html

[NihalKarne]

when i try to execute index.html from admin folder its shows the loading bar and get stuck. I checked the console and I found this error

Uncaught TypeError: Cannot set property 'id' of undefined
    at main.js:37
    at Array.map (<anonymous>)
    at main.js:35
    at VM92 firebase.js:1
    at Ue (VM92 firebase.js:1)
    at t.raise (VM92 firebase.js:1)
    at t.raiseQueuedEventsMatchingPredicate_ (VM92 firebase.js:1)
    at t.raiseEventsForChangedPath (VM92 firebase.js:1)
    at t.onDataUpdate_ (VM92 firebase.js:1)
    at e.onDataPush_ (VM92 firebase.js:1)
(anonymous) @ main.js:37
(anonymous) @ main.js:35
(anonymous) @ index.esm.js:4458
Ue @ index.esm.js:684
t.raise @ index.esm.js:9720
t.raiseQueuedEventsMatchingPredicate_ @ index.esm.js:9674
t.raiseEventsForChangedPath @ index.esm.js:9658
t.onDataUpdate_ @ index.esm.js:12760
e.onDataPush_ @ index.esm.js:12060
e.onDataMessage_ @ index.esm.js:12054
t.onDataMessage_ @ index.esm.js:11331
t.onPrimaryMessageReceived_ @ index.esm.js:11325
(anonymous) @ index.esm.js:11226
t.appendFrame_ @ index.esm.js:10831
t.handleIncomingFrame @ index.esm.js:10881
mySock.onmessage @ index.esm.js:10778
setTimeout (async)
Ue @ index.esm.js:688
t.raise @ index.esm.js:9720
t.raiseQueuedEventsMatchingPredicate_ @ index.esm.js:9674
t.raiseEventsForChangedPath @ index.esm.js:9658
t.onDataUpdate_ @ index.esm.js:12760
e.onDataPush_ @ index.esm.js:12060
e.onDataMessage_ @ index.esm.js:12054
t.onDataMessage_ @ index.esm.js:11331
t.onPrimaryMessageReceived_ @ index.esm.js:11325
(anonymous) @ index.esm.js:11226
t.appendFrame_ @ index.esm.js:10831
t.handleIncomingFrame @ index.esm.js:10881
mySock.onmessage @ index.esm.js:10778