500 Internal Server Error

Technical details:
Error: Not array - for
***  in function "Z_lookup_parent"
***  line: [(Unknown), (Unknown), (Unknown)] = (({L2})["links"])[{L4}]
***  call: Z_lookup_parent ([[ix_db], [ix_dd], [ix_recmon], [ix_sparse]], [TABLE], [TABLE], 0)
***  call: Z_mkurl ([[ix_db], [ix_dd], [ix_recmon], [ix_sparse]], "SITE-COL", [TABLE])