Python warning and 'apply fail' when deleting an NFS share

Error #0:
OMV\ExecException: Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C.UTF-8; omv-salt deploy run nfs 2>&1' with exit code '1': /usr/lib/python3/dist-packages/salt/utils/decorators/signature.py:31: DeprecationWarning: `formatargspec` is deprecated since Python 3.5. Use `signature` and the `Signature` object directly
  *salt.utils.args.get_function_argspec(original_function)
/usr/lib/python3/dist-packages/salt/utils/decorators/signature.py:31: DeprecationWarning: `formatargspec` is deprecated since Python 3.5. Use `signature` and the `Signature` object directly
  *salt.utils.args.get_function_argspec(original_function)
/usr/lib/python3/dist-packages/salt/utils/decorators/signature.py:31: DeprecationWarning: `formatargspec` is deprecated since Python 3.5. Use `signature` and the `Signature` object directly
  *salt.utils.args.get_function_argspec(original_function)
debian:
----------
          ID: configure_default_nfs-kernel-server
    Function: file.managed
        Name: /etc/default/nfs-kernel-server
      Result: True
     Comment: File /etc/default/nfs-kernel-server is in the correct state
     Started: 10:50:01.873922
    Duration: 157.951 ms
     Changes:
----------
          ID: configure_nfsd_exports
    Function: file.managed
        Name: /etc/exports
      Result: True
     Comment: File /etc/exports is in the correct state
     Started: 10:50:02.032167
    Duration: 198.301 ms
     Changes:
----------
          ID: start_rpc_statd_service
    Function: service.running
        Name: rpc-statd
      Result: True
     Comment: The service rpc-statd is already running
     Started: 10:50:04.089224
    Duration: 102.912 ms
     Changes:
----------
          ID: start_nfs_kernel_server_service
    Function: service.running
        Name: nfs-kernel-server
      Result: False
     Comment: Job for nfs-server.service canceled.
     Started: 10:50:04.195751
    Duration: 246.768 ms
     Changes:


Summary for debian
------------
Succeeded: 3
Failed:    1
------------
Total states run:     4
Total run time: 705.932 ms in /usr/share/php/openmediavault/system/process.inc:182
Stack trace:
#0 /usr/share/php/openmediavault/engine/module/serviceabstract.inc(60): OMV\System\Process->execute()
#1 /usr/share/openmediavault/engined/rpc/config.inc(167): OMV\Engine\Module\ServiceAbstract->deploy()
#2 [internal function]: Engined\Rpc\Config->applyChanges(Array, Array)
#3 /usr/share/php/openmediavault/rpc/serviceabstract.inc(123): call_user_func_array(Array, Array)
#4 /usr/share/php/openmediavault/rpc/serviceabstract.inc(149): OMV\Rpc\ServiceAbstract->callMethod('applyChanges', Array, Array)
#5 /usr/share/php/openmediavault/rpc/serviceabstract.inc(588): OMV\Rpc\ServiceAbstract->OMV\Rpc\{closure}('/tmp/bgstatusYU...', '/tmp/bgoutputo5...')
#6 /usr/share/php/openmediavault/rpc/serviceabstract.inc(159): OMV\Rpc\ServiceAbstract->execBgProc(Object(Closure))
#7 /usr/share/openmediavault/engined/rpc/config.inc(189): OMV\Rpc\ServiceAbstract->callMethodBg('applyChanges', Array, Array)
#8 [internal function]: Engined\Rpc\Config->applyChangesBg(Array, Array)
#9 /usr/share/php/openmediavault/rpc/serviceabstract.inc(123): call_user_func_array(Array, Array)
#10 /usr/share/php/openmediavault/rpc/rpc.inc(86): OMV\Rpc\ServiceAbstract->callMethod('applyChangesBg', Array, Array)
#11 /usr/sbin/omv-engined(537): OMV\Rpc\Rpc::call('Config', 'applyChangesBg', Array, Array, 1)
#12 {main}