Getting a TextBlock variable from the Return Value of a Create Widget node inside a Player Controller will cancel all the nodes before it in Standalone. Does not occur in other PIE modes, and does not seem to occur in other Blueprints. This did not occur in 4.7.6.
A workaround is to add a variable in the Graph of the widget. Simply having a variable in there stops this from happening.
Reproduced in 4.8 Preview 2 and Main (//depot/UE4/Promotable-CL-2552010)
1. Open any project
2. Create a new Widget Blueprint
3. Add a Textbox
4. Make the Textbox a variable
5. Create a new Player Controller
6. Set the new Player Controller in the GameMode
7. Event Begin Play > Print String > Create Widget
8. From the Return Value, Get the Textbox variable
9. Play in Standalone mode
The Print String does not run. If you do more with the Textbox variable (such as SetText(Text)), that is not run either.
Head over to the existing Questions & Answers thread and let us know what's up.