Hi @Martin_D,
I could be wrong, but it appears that vseasrch clustering is working, but failing at the writing stage? 
Could it be a storage issue? Otherwise, I agree that it could be a memory issue with post processing, as it appears that your machine has ~16 GB not ~32 GB of RAM:
On another note, I'd likely set --p-mode to uniq, lca, or majority, instead of super. At least, you should be aware of how super works, as outlined here.
-Mike