SQL Table Error - DB error - Duplicate entry

[Karange]

Hey folks -

First I'll apologize as my knowledge in SQL is limited, and just started this project with a brother of mine. Just recently (within the past 6 hours) we started getting this particular SQL Error code:

 

[SQL]: DB error - Duplicate entry '235904' for key 'picklog.PRIMARY'
[Debug]: at C:\Users\Hermitage RO\Desktop\HermitageRO\rathena\src\map\log.cpp:239 - INSERT DELAYED INTO `picklog` (`time`, `char_id`, `type`, `nameid`, `amount`, `refine`, `map`, `unique_id`, `bound`, `card0`, `card1`, `card2`, `card3`, `option_id0`, `option_val0`, `option_parm0`, `option_id1`, `option_val1`, `option_parm1`, `option_id2`, `option_val2`, `option_parm2`, `option_id3`, `option_val3`, `option_parm3`, `option_id4`, `option_val4`, `option_parm4`) VALUES(NOW(),'150013','C','602','-1','0','iz_dun01','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0')

If anyone who is a bit more familiar with SQL than me has the heart to give me some detailed information on how to possibly fix this issue, that would help greatly, and as always I appreciate any help/guidance!

Edit: Just realized I posted this in the wrong Support section, which I apologize about. 
 

Edited May 5, 2020 by Karange
Adjusted title.

[Kreustoo]

Happened one time or happens regulary? In what situation?