antoineco Steps to reproduce: Navigate to Tools > Extensions > Popular Extensions and install "LastPass". Log in, pick any item from the vault (password, note, ...) and copy any of the information it contains. A prompt asks you for permissions to read/write from/to the clipboard. Accept it. See Why am I being asked for permission in Firefox to copy LastPass data to my clipboard? Try to paste the information you just copied, and observe that no information was actually copied to the clipboard. Expected behavior: The information is written to the OS' clipboard and can be pasted. Debug info: Version 0.99.120-beta (WebKit 614.1.20) MacBook Pro (macOS Monterey 12.6 build 21G115) Image/Video: n/a Additional notes: I suspect this might be a common issue with all Firefox extensions, but haven't had a chance to check that assumption. See also 1password extension Copy button not copying to clipboard.