During Import Data Dictionary after pressing Continue button in ttiex1285 we receive such an error:
Process <n> - Fatal error : bis_alloc_mem: sym ' ', i=0
The subsession ttiex1288 does not start.

I have already removed user defaults (found in one of previous threads about bis_alloc_mem), it didn't help.
Same error occurs in bw and ba.

The environment is: SCO, BaaN IV c4 with tbase. What can be wrong?

The error basically indicates that you ran out of memory.

Off the cuff, I would say that you need to check your configuration, and more specifically, the shared memory allocation, given that this happens when importing the DD.