uMatrix and NoScript access rules
By default, the uMatrix and NoScript extensions may block the Bitwarden Firefox extension from accessing the Bitwarden API servers. Without adding proper rules to whitelist the Bitwarden API servers, logging in and other API operations will fail.
The following uMatrix rule is required:
Bashdc8ef5f6-eb0d-4c87-9e9f-0cf803f619e8.moz-extension-scheme bitwarden.com xhr allow
note
The UUID included in the above rule (dc8ef5f6-eb0d-4c87-9e9f-0cf803f619e8) will be different for your installation.
Use the about:debugging#/runtime/this-firefox page (navigate from Firefox's address bar) to locate your Bitwarden extension UUID.
Whitelisting the following domain in NoScript is required: bitwarden.com