Error activating LV 'pve/data'

[mammutserver]

After a restart of my server I get the following error:

TASK ERROR: activating LV 'pve/data' failed:   Check of pool pve/data failed (status:1). Manual repair required!

I tried lvconvert --repair pve/data and got this output:

truncating metadata device to 4161600 4k blocks

  Child 3798 exited abnormally
  Repair of thin metadata volume of thin pool pve/data failed (status:-1). Manual repair required!

What can I do?