Unknown offset -1 for collection OrderPayment

[Sharak]

*ERROR* 	2017/10/26 - 01:52:49: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php
*ERROR* 	2017/10/26 - 02:02:33: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php
*ERROR* 	2017/10/26 - 02:17:40: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php
*ERROR* 	2017/10/26 - 02:22:51: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php
*ERROR* 	2017/10/26 - 02:32:45: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php
*ERROR* 	2017/10/26 - 02:47:51: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php
*ERROR* 	2017/10/26 - 02:52:53: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php
*ERROR* 	2017/10/26 - 03:02:57: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php
*ERROR* 	2017/10/26 - 03:18:03: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php
*ERROR* 	2017/10/26 - 03:22:55: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php
*ERROR* 	2017/10/26 - 03:33:09: Unknown offset -1 for collection OrderPayment at line 482 in file classes/PrestaShopCollection.php

I get like few hundreds of these errors every day in my logs. What can be the cause of that? Everything seems to work ok. Prestashop 1.6.1.17

[tuk66]

Unfortunately, only the error is not enough to catch the problem in this case. Can you get more detailed stack trace?

http://php.net/manual/en/function.debug-backtrace.php

[Sharak]

How exactly should I use this function? I don't even know which variable or function is causing it