Help with using variables in other blueprints gives error

help i cant figure this out im trying to have it where when i enter a trigger box it adds to a variable that adds to a textbox on my UI but when ever i enter the trigger box the output console log gives this error:

LogScript:Warning: Accessed None ‘ThisFile’
MainGameMap_C /Game/Maps/UEDPIE_0_MainGameMap.MainGameMap:PersistentLevel.MainGameMap_C_1
Function /Game/Maps/MainGameMap.MainGameMap_C:ExecuteUbergraph_MainGameMap:02A0
PIE:Error: Error Accessed None ‘ThisFile’ from node Set Test1 in blueprint MainGameMap
LogScript:Warning: Accessed None ‘ThisFile’
MainGameMap_C /Game/Maps/UEDPIE_0_MainGameMap.MainGameMap:PersistentLevel.MainGameMap_C_1
Function /Game/Maps/MainGameMap.MainGameMap_C:ExecuteUbergraph_MainGameMap:02C3
PIE:Error: Error Accessed None ‘ThisFile’ from node Set Test1 in blueprint MainGameMap
LogScript:Warning: Attempt to assign variable through None
MainGameMap_C /Game/Maps/UEDPIE_0_MainGameMap.MainGameMap:PersistentLevel.MainGameMap_C_1
Function /Game/Maps/MainGameMap.MainGameMap_C:ExecuteUbergraph_MainGameMap:02D9
PIE:Error: Error Attempt to assign variable through None from node Set Test1 in blueprint MainGameMap