Failed to execute git checkout '3e87f7365d79a7f33f4aea3fa5cc7e17b6c56305' -- && git reset --hard '3e87f7365d79a7f33f4aea3fa5cc7e17b6c56305' -- fatal: unable to read tree (3e87f7365d79a7f33f4aea3fa5cc7e17b6c56305) It looks like the commit hash is not available in the repository, maybe the commit was removed from the branch? Run "composer update silverstripe/framework" to resolve this.