A memory leak was found in the hybrid functional part of vasp.126.96.36.199Jun15.
A patch (patch.5.4.1.06112015) that fixes this problem can be downloaded from the download portal or our wiki.
Gunzip and apply this patch inside the vasp.5.4.1 root directory:
patch -p1 < patch.5.4.1.06112015
Sorry for the inconvenience,
The VASP team.