SecurityError: Blocked a frame with origin "https://etherpad.acme.com" from accessing a cross-origin frame.

[m0urs]

I am quite sure my Etherpad integration into Nextcloud has been working for some time and maybe one of the last updates of Nextcloud broke it.

I can succesfully create a new pad (either public or protected). However, if I try to open it, I get the following error message in a red box:

An error occurred
Please press and hold Ctrl and press F5 to reload this page

If the problem persists, please send this error message to your webmaster:

SecurityError: Blocked a frame with origin "https://etherpad.acme.com" from accessing a cross-origin frame.
at unknown at line -1
ErrorId: jhApKeMjo1NzDQWEWFtx
Unhandled Promise rejection
URL: https://etherpad.acme.com/p/g.xxxxxxxxxxxxxxxxxxxxxxx
UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36 Edg/110.0.1587.46

In the Etherpad log there is the following error message:

'Error: Blocked a frame with origin "https://etherpad.acme.com" from accessing a cross-origin frame.
        at exports.aceSelectionChanged [as hook_fn] (eval at <anonymous> (https://etherpad.acme.com/static/js/require-kernel.js?v=10e36018:1:1), <anonymous>:48:41)
        at callHookFnSync (eval at <anonymous> (https://etherpad.acme.com/static/js/require-kernel.js?v=10e36018:1:1), <anonymous>:12803:16)
        at eval (eval at <anonymous> (https://etherpad.acme.com/static/js/require-kernel.js?v=10e36018:1:1), <anonymous>:12876:54)
        at Array.map (<anonymous>)
        at exports.callAll (eval at <anonymous> (https://etherpad.acme.com/static/js/require-kernel.js?v=10e36018:1:1), <anonymous>:12876:25)
        at repSelectionChange (eval at <anonymous> (https://etherpad.acme.com/static/js/require-kernel.js?v=10e36018:1:1), <anonymous>:2016:13)
        at performSelectionChange (eval at <anonymous> (https://etherpad.acme.com/static/js/require-kernel.js?v=10e36018:1:1), <anonymous>:1987:9)
        at setDocAText (eval at <anonymous> (https://etherpad.acme.com/static/js/require-kernel.js?v=10e36018:1:1), <anonymous>:540:5)
        at setDocText (eval at <anonymous> (https://etherpad.acme.com/static/js/require-kernel.js?v=10e36018:1:1), <anonymous>:551:5)
        at eval (eval at <anonymous> (https://etherpad.acme.com/static/js/require-kernel.js?v=10e36018:1:1), <anonymous>:485:7)'

Nextcloud Version: 25.0.3
Etherpad Version: 1.8.18
Ownpad Version: 0.7.1

In Nextcloud I have the following settings for Ownpad:

Etherpad Host: https://etherpad.acme.com
Etherpad API enabled and the correct API key configured
Etherpad Cookie domain: "acme.com"

My Etherpad instance is running with the URL: https://etherpad.acme.com
My Nextcloud instance is running with the URL: https://nextcloud.acme.com

I also disabled all security restrictions I had configured in my Apache CONF files for both instances but without success.

I appreciate any hint what is going wrong here.

[otetard]

Can you check if you still encounter this issue with the latest version of Ownpad (0.8.1) please?

[otetard]

This seems to be a configuration issue related to Etherpad rather than Ownpad.

[m0urs]

It is still not working. Unfortunately I have no idea what kind of configuration error it could be. It did work earlier and stopped suddenly with a new version of Nextcloud or Ownpad. It does work stand alone (outside of Nextcloud).

[otetard]

The strange thing in your posted stacktrace, is that the error occurs in Etherpad’s code, not in Ownpad’s. It seems that Etherpad is trying to a request to the wrong domain.

Can you do a screenshot of your browser’s devtool “network” tab please?

[m0urs]

I guess, the issue is because of the different hostnames for Nextcloud (nextcloud.acme.com) and Etherpad (etherpad.acme.com). However, it did work for me in this configuration some time ago.