I have had this problem for some time, on the admin custom grid. can anyone tell me any solution to this ?
Check This Below Screenshot For Reference:
Before proceeding, make sure to take a backup of your database and the affected tables, or work on a staging/development environment to avoid any potential data loss.
SELECT * FROM salesrule WHERE your_serialized_field LIKE '%s: %';
Replace your_serialized_field with the specific column that contains the serialized data.
Remove Invalid Entries.