YES! this is exactly what I need.  

Ah I wished you had made that change yesterday.  ;)

Actually, default delete cookies on my system was last 4 weeks.  I did that, did not help.

Then I deleted all cookies since beginning of time, that worked.  It however is a super pain.  I am a web developer myself, managing a lot of different systems and deleting cookies to access Vertabelo is not viable.  I have dozens of systems I manage and maintain and wiping out everything anytime I need to get into vertabelo will cost me too much time.  If this persists we will have to cancel.

Did that.  No change, same error.

No change.  Here is the console log:

common.js?v=3.7.4:284 Trying to reconnect to server
common.js?v=3.7.4:284 Trying to reconnect to server
webapp.js?v=3.7.4:376 [{…}, callee: ƒ, Symbol(Symbol.iterator): ƒ]
VM458:161 WebSocket connection to 'wss://ws-user.vertabelo.com/ws' failed: Error during WebSocket handshake: Unexpected response code: 404
WrappedWebSocket @ VM458:161
c @ common.js?v=3.7.4:276
(anonymous) @ common.js?v=3.7.4:278
fire @ jquery.js:3148
fireWith @ jquery.js:3260
done @ jquery.js:9314
callback @ jquery.js:9718
common.js?v=3.7.4:284 Error occured while communicating with server  Event {isTrusted: true, type: "error", target: WebSocket, currentTarget: WebSocket, eventPhase: 2, …}
common.js?v=3.7.4:284 Websocket closed abnormally. CloseEvent {isTrusted: true, wasClean: false, code: 1006, reason: "", type: "close", …}
common.js?v=3.7.4:284 Trying to reconnect to server
common.js?v=3.7.4:284 Trying to reconnect to server
VM458:161 WebSocket connection to 'wss://ws-user.vertabelo.com/ws' failed: Error during WebSocket handshake: Unexpected response code: 404
WrappedWebSocket @ VM458:161
c @ common.js?v=3.7.4:276
(anonymous) @ common.js?v=3.7.4:278
fire @ jquery.js:3148
fireWith @ jquery.js:3260
done @ jquery.js:9314
callback @ jquery.js:9718
common.js?v=3.7.4:284 Error occured while communicating with server  Event {isTrusted: true, type: "error", target: WebSocket, currentTarget: WebSocket, eventPhase: 2, …}
common.js?v=3.7.4:284 Websocket closed abnormally. CloseEvent {isTrusted: true, wasClean: false, code: 1006, reason: "", type: "close", …}
VM458:161 WebSocket connection to 'wss://ws-user.vertabelo.com/ws' failed: Error during WebSocket handshake: Unexpected response code: 404
WrappedWebSocket @ VM458:161
c @ common.js?v=3.7.4:276
(anonymous) @ common.js?v=3.7.4:278
fire @ jquery.js:3148
fireWith @ jquery.js:3260
done @ jquery.js:9314
callback @ jquery.js:9718
common.js?v=3.7.4:284 Error occured while communicating with server  Event {isTrusted: true, type: "error", target: WebSocket, currentTarget: WebSocket, eventPhase: 2, …}
common.js?v=3.7.4:284 Websocket closed abnormally. CloseEvent {isTrusted: true, wasClean: false, code: 1006, reason: "", type: "close", …}
common.js?v=3.7.4:284 Trying to reconnect to server
common.js?v=3.7.4:284 Trying to reconnect to server
common.js?v=3.7.4:284 Trying to reconnect to server
common.js?v=3.7.4:284 Trying to reconnect to server
VM458:161 WebSocket connection to 'wss://ws-user.vertabelo.com/ws' failed: Error during WebSocket handshake: Unexpected response code: 404
WrappedWebSocket @ VM458:161
c @ common.js?v=3.7.4:276
(anonymous) @ common.js?v=3.7.4:278
fire @ jquery.js:3148
fireWith @ jquery.js:3260
done @ jquery.js:9314
callback @ jquery.js:9718
common.js?v=3.7.4:284 Error occured while communicating with server  Event {isTrusted: true, type: "error", target: WebSocket, currentTarget: WebSocket, eventPhase: 2, …}
common.js?v=3.7.4:284 Cannot connect to server. Number of retries = 6
common.js?v=3.7.4:284 Websocket closed abnormally. CloseEvent {isTrusted: true, wasClean: false, code: 1006, reason: "", type: "close", …}

No still getting kicked back to the "Oops we have a problem...reload page" then kicked back to login.  Will try clearing cache and cookies and try again

Cleared all vertabelo history.  Was able to login, but get:

Oops we've got a problem. Something went wrong ... Reload page

Which then kicks me back to the Login page.

Tried Firefox: not supported

Tried Edge: works for now.

Still getting this error.  Cleared cookies, and everything else on the Application panel.

To be clear, we have no way of accessing his account. I just need to delete his documents and his user account. There does not seem to be a way for an administrator to do this.