System update failed of invalid signatures

[Wollie]

Maybe the wiki contains some helpful ideas:

Pacman troubleshooting

Also, check this thread:

[HowTo] Solve Keyring Related Issues in Manjaro

Wiki Page: Manjaro and Arch users have a security keyring on their machine that allows them to safely download packages from the Manjaro and Arch repositories without those packages getting tampered with by a man-in-the-middle-attack. Sometimes if a user doesn’t update their system for a long time, this keyring might expire. The keyring can also get corrupted for some reason. To solve basic keyring issues do the following: Resynchronise with the Manjaro repository servers to ensure that eve…