Error in ArrayType.php line 58


I’m running Mautic v2.12.2 on PHP Version 7.0.27

The log is repeatedly showing error:

[2018-03-31 10:30:31] mautic.NOTICE: PHP Notice - unserialize(): Error at offset 135 of 148 bytes - in file /pathto/mautic/vendor/doctrine/dbal/lib/Doctrine/DBAL/Types/ArrayType.php - at line 58 [] []

Anybody know a way to fix issue or if it is critical?

Thank you!
Bob H.