Amei mas estou com alguns erros.

09:17:01.939
TypeError: node.tagName is undefined content_script.js:322:9

09:17:02.049
this.nativeTab.linkedBrowser is null

09:17:37.324
TypeError: node.tagName is undefined content_script.js:322:9
isForbiddenNode moz-extension://60bc6b7e-f74f-4813-af20-01190fe2e932/content_script.js:322
replaceNodes moz-extension://60bc6b7e-f74f-4813-af20-01190fe2e932/content_script.js:333
forEach self-hosted:208
replaceNodes moz-extension://60bc6b7e-f74f-4813-af20-01190fe2e932/content_script.js:330
processQueue moz-extension://60bc6b7e-f74f-4813-af20-01190fe2e932/content_script.js:255
forEach self-hosted:208
processQueue moz-extension://60bc6b7e-f74f-4813-af20-01190fe2e932/content_script.js:254
observerCallback moz-extension://60bc6b7e-f74f-4813-af20-01190fe2e932/content_script.js:285
09:17:37.336
null has no properties