not possible to create homedirectory for users

Fehler #0:
exception 'OMV\ExecException' with message 'Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C; usermod --move-home --home '/media/e994f4bb-9c6a-484d-8feb-d4f811b50791/Homeverzeichnis/openvpn_as' 'openvpn_as' 2>&1' with exit code '8': usermod: user openvpn_as is currently used by process 10510' in /usr/share/php/openmediavault/system/process.inc:174
Stack trace:
#0 /usr/share/openmediavault/engined/rpc/usermgmt.inc(1080): OMV\System\Process->execute()
#1 [internal function]: OMVRpcServiceUserMgmt->setSettings(Array, Array)
#2 /usr/share/php/openmediavault/rpc/serviceabstract.inc(124): call_user_func_array(Array, Array)
#3 /usr/share/php/openmediavault/rpc/rpc.inc(84): OMV\Rpc\ServiceAbstract->callMethod('setSettings', Array, Array)
#4 /usr/sbin/omv-engined(516): OMV\Rpc\Rpc::call('UserMgmt', 'setSettings', Array, Array, 1)
#5 {main}