When a user deleted a widget that has been added to another blueprint via the user created section. If this blueprint in referenced in another blueprint that reference will throw a REINST error and cause pins to be disconnected.
There is a video that can be found on the original thread
Expected: The Widget would reference would be replaced with the new one that was provided 
Result: The new widget reference is rejected 
Head over to the existing Questions & Answers thread and let us know what's up.
| 0 | 
| Component | UE - Gameplay - Blueprint | 
|---|---|
| Affects Versions | 4.9.2 | 
| Created | Oct 5, 2015 | 
|---|---|
| Resolved | Jul 14, 2016 | 
| Updated | Jul 14, 2021 |