While trying to debug a program I am kicking off a "child" session using SQL window and trying to look at the data.
unfortunately, as i have to deal with the table of more then 60 columns i am getting ORA - 6558 buffer in dbms_pipe is full.
Now - that is of course not PL/SQL error. However, when i decrease amount of columns to about 10 I get ora - 6502.
Can you please look into that 6502 ?

(it appears that your grid misreading statement for the datatypes)