Failed to execute git checkout 'a4e5d51d2b9d23102f23df2ae3b37771dfe30c69' -- && git reset --hard 'a4e5d51d2b9d23102f23df2ae3b37771dfe30c69' -- fatal: reference is not a tree: a4e5d51d2b9d23102f23df2ae3b37771dfe30c69 It looks like the commit hash is not available in the repository, maybe the commit was removed from the branch? Run "composer update wporg/wporg-mu-plugins" to resolve this.