Steps to reproduce:

If possible, please share specific steps to reproduce the error.
Otherwise add any additional information useful to investigate the issue.

Error in Web Developer Tools:

Error: Protocol error (SecurityError): Permission denied to access property "document" on cross-origin object from: server0.conn0.watcher3 (resource://devtools/server/actors/webconsole/listeners/document-events.js:66:11)

Client Packet:

{
  "type": "watchResources",
  "resourceTypes": [
    "document-event"
  ],
  "to": "server0.conn0.watcher3"
}

Server Packet:

{
  "from": "server0.conn0.watcher3",
  "error": "SecurityError",
  "message": "Permission denied to access property \"document\" on cross-origin object",
  "fileName": "resource://devtools/server/actors/webconsole/listeners/document-events.js",
  "lineNumber": 66,
  "columnNumber": 11
}

Server Stack:

listen@resource://devtools/server/actors/webconsole/listeners/document-events.js:66:11
watch@resource://devtools/server/actors/resources/document-event.js:103:19
watchResources@resource://devtools/server/actors/resources/index.js:371:15
addOrSetSessionDataEntry@resource://devtools/server/actors/targets/session-data-processors/resources.js:19:21
addOrSetSessionDataEntry@resource://devtools/server/actors/targets/base-target-actor.js:87:23
#addOrSetSessionDataEntry@resource://devtools/server/connectors/js-process-actor/DevToolsProcessChild.sys.mjs:398:21
receiveMessage@resource://devtools/server/connectors/js-process-actor/DevToolsProcessChild.sys.mjs:323:46

Stacktrace:

onPacket/<@resource://devtools/shared/protocol/Front.js:404:31
DevTools RDP*request@resource://devtools/shared/protocol/Front.js:320:14
generateRequestMethods/</frontProto[name]@resource://devtools/shared/protocol/Front/FrontClassWithSpec.js:57:19
_startListening@resource://devtools/shared/commands/resource/resource-command.js:1083:31

Thanks for the report.

Normally the issues for cross-origin document errors should be fixed in Firefox 2003810, which was just fixed in the latest version of Firefox 147.0.3. Do you know if you were still on 147.0.2 or lower when you had the issue?

I am on the most recent version. 148.0b11

Thanks for the feedback, regarding the beta channel, the patch should have been there starting with 148.0b7, so it looks like the fix from Bug 2003810 didn't fully address the issue.