No connection to TeamViewer Server

Since yesterday the error "No connection to TeamViewer Server - Please check your internet connection" always appears.
Yesterday I had installed the insider-version, but then uninstalled it again because of the problem.
In the log are these errors (the ID is censored):
SecureNetworkConnection :: SendCallbackHandler (): [remoteID: 14 connection: 0 remoteConnection: 0], Error: RCommand (timeout)
SecureNetworkConnection :: SendCallbackHandler (): [remoteID: 14 connection: 0 remoteConnection: 0] Resetting connection due to error RCommand (Timeout)
HandshakeClient :: Connect: [remote ID: 46, connection ID: XXXXXXXXXX, remote connection ID: 0] invalid private key "