Unable to establish connection with iframe

[Maus0728]

I am trying to add multiple accounts to Metamask using the "Connect Hardware Wallet" function on the Metask GUI, but the thing is, there is an error showing "Popup error: Unable to establish connection with iframe".

Quick fix that I have tried:

- disabling all of my browser extension such as HTTPS Everywhere, Decentraleyes and UBlock Origin
- Changed my browser privacy settings from Custom to Standard
- I unlocked the Trezor before clicking the "Connect Hardware Wallet" in metamask.
- installed the latest Trezor Bridge here: https://suite.trezor.io/web/bridge/
- system restart

This is the link to where I downloaded the extension for metamask: https://addons.mozilla.org/en-US/firefox/addon/ether-metamask/

[witcher_sense]

I am trying to add multiple accounts to Metamask using the "Connect Hardware Wallet" function on the Metask GUI, but the thing is, there is an error showing "Popup error: Unable to establish connection with iframe".

Quick fix that I have tried:

- disabling all of my browser extension such as HTTPS Everywhere, Decentraleyes and UBlock Origin
- Changed my browser privacy settings from Custom to Standard
- I unlocked the Trezor before clicking the "Connect Hardware Wallet" in metamask.
- installed the latest Trezor Bridge here: https://suite.trezor.io/web/bridge/
- system restart

This is the link to where I downloaded the extension for metamask: https://addons.mozilla.org/en-US/firefox/addon/ether-metamask/

It is a known problem, Trezor doesn't want to work with Metamask installed in Firefox browser:

https://github.com/MetaMask/metamask-extension/issues/11502
https://github.com/MetaMask/metamask-extension/issues/11042
https://github.com/MetaMask/metamask-extension/issues/10896
https://github.com/trezor/connect/issues/784

Try installing a different browser: Tor based on Mozilla Firefox 91.3.0esr or higher, Google Chrome, Brave...

[dkbit98]

I am trying to add multiple accounts to Metamask using the "Connect Hardware Wallet" function on the Metask GUI, but the thing is, there is an error showing "Popup error: Unable to establish connection with iframe".

You didn't say what browser you used (that could be one of this issues) but I know many users are still reporting problems with Metamask using all hardware wallets.
Best solution for this issue is to use official Trezor Suite wallet directly, instead of messing around with metamask wallet and browsers.
You can also create multiple accounts there and have a better privacy with Tor support.

[Maus0728]

Update

It's odd to see that the integration between Trezor and Metamask is now working. I'm not sure how it works; I just reset all of my Firefox browser settings and enabled all of the extensions, then I restarted my browser, connected the HW, and it worked. One thing I am certain of is that none of the extensions have anything to do with the iframe connection problem.

Thanks everyone. I will now lock this thread.