Error Inventory System .Blueprint Runtime Error: "Accessed None trying to read property K2Node_Event_Player".

When I try to add an item to my inventory using mechanics, I get this error, I can’t understand the reason, I looked through the entire script and couldn’t find anything.

Blueprint Runtime Error: “Accessed None trying to read property K2Node_Event_Player”. Node: Add to Inventory Graph: EventGraph Function: Execute Ubergraph Master Ispection Item Blueprint: Master_Ispection_Item

The error message links directly to the issue. Click the underline text in the message to jump to the problem.