MetaMask spins forever on failed options request to custom endpoint.

[MicahZoltu]

Describe the bug
MetaMask does not inform the user of an error connecting to a custom endpoint, instead just spinning forever.

To Reproduce
Steps to reproduce the behavior:

1. Setup Parity on a cloud server and forget to set --jsonrpc-cors=all
2. In MetaMask, click the Network chooser dropdown and choose Custom RPC
3. Fill in details that point to Parity server.
4. Notice that the UI just spins forever.

Expected behavior
The UI provides a clear error and gives up.

Browser details (please complete the following information):

• OS: Windows 10
• Browser: Firefox
• MetaMask Version: 4.17.1
• Beta (I think)

Additional context
Failing to include --jsonrpc-cors=all on the Parity node will result in it returning 403 responses to the MetaMask OPTIONS preflight request. MetaMask appears to just retry this request indefinitely, never alerting the user about it. I had to debug the extension to even see the error in the network tab.

You can also reproduce this behavior by setting up a tiny little webserver that just responds to all OPTIONS requests with 403.

[bdresser]

@MicahZoltu closing as a duplicate of #3776, we think this can be solved with a better UI but are open to other thoughts!

[danfinlay]

I'm not sure it's a perfect duplicate, since this is a specific problem we could detect and represent to the user, making their time easier. #3776 is a generic failure, and doesn't help the user debug what's wrong.

[majikandy]

This is related to the endpoint not being there.... for example it happened in my case when I forgot to put the port on the end of the url.

The only solution, currently, seems to be to remove the extension, re add and then restore from seed.

Even when rebooting it is still stuck in the spinning "Connecting to unknown network" when clicking on metamask

[kliu128]

I am hitting the same issue. Very annoying that you can't change the network, since the network spinner covers it.

[bdresser]

This is fixed for the basic case (filed in #3776 and #5609) by #5893 – we'll make the network dropdown available while attempting to connect, and we'll time out requests after 15s and prompt the user to switch networks or try again.

The fix doesn't provide detailed error messages described by OP, so we can leave this open.