When users cannot logon to TPX and the TPX Log shows messages like
TPXL0400 <date> <time> VSAM ERROR. KEY = xxxxxxx
RTNCD/FDBK = 00080020
REQUEST TYPE = 00
RBA = 0000000000000000
then a possible cause is that the VSAM VSI record in the TPX VSAM files which contains information's for file sharing between TPX regions is corrupted. We call this VSI record 'record 0' in TPX. It contains information's like the volume, the catalogue where the VSAM-file resides, high-used RBA etc.