Just tried to reproduce this bug in fresh 4.16 preview from Launcher. With success. Same blueprint, from above, same error. Version: 4.16.0-3405315+++UE4+Release-4.16
LogLoad: Game class is 'GameModeBase'
LogWorld: Bringing World /Game/StarterContent/Maps/UEDPIE_0_Minimal_Default.Minimal_Default up for play (max tick rate 0) at 2017.04.26-14.45.04
LogWorld: Bringing up level for play took: 0.001545
LogScript:Warning: Accessed None trying to property NewVar_0
Minimal_Default_C /Game/StarterContent/Maps/UEDPIE_0_Minimal_Default.Minimal_Default:PersistentLevel.Minimal_Default_C_1
Function /Game/StarterContent/Maps/Minimal_Default.Minimal_Default_C:ExecuteUbergraph_Minimal_Default:0028
PIE:Error: Error Blueprint Runtime Error: Accessed None trying to property NewVar_0 from function: 'ExecuteUbergraph_Minimal_Default' from node: Print String in graph: EventGraph in object: Minimal_Default with description: Accessed None trying to property NewVar_0
LogBlueprintUserMessages: [Minimal_Default_C_1] X=0.000 Y=0.000 Z=0.000
PIE: Info Play in editor start time for /Game/StarterContent/Maps/UEDPIE_0_Minimal_Default 0.526
Should this happen? Is this bug fixed in 4.16 final but not in preview?