Re-launch Radicle Upstream application

I get an error trying to re-launch Radicle Upstream application (as root).
Error: Sled(Io(Custom { kind: Other, error: “could not acquire lock on “/root/.local/share/radicle-upstream/store/db”: Os { code: 11, kind: WouldBlock, message: “Resource temporarily unavailable” }” }))
It worked correctly the first time.
How can I fix this?