I need some help with a legacy software in Common.php

Hello Srs.
I am sorry if this is not the right place for this question.
I am on charge of a legacy software made in codeigniter 2.x and I need some help with the error_log.
I can't clean the bugs because the error_log does not save anything. It just writes:
[13-Feb-2023 21:50:00 America/Caracas] PHP Deprecated:  Required parameter $message follows optional parameter $level ~/system/core/Common.php on line 351
If some of you knows what can I do, please, could you explain me?
Thank you and have a good week.

Required parameter $message follows optional parameter $level ~/system/core/Common.php on line 351

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