After Seamless Server Travel, the Client cannot move the character or see the Server character. On the Server, the Client character appears to be falling in place. Tested in both first and third person projects.
Reproduced in 4.7.6, 4.8.1 binary, and Main (//depot/UE4/Promotable-CL-2614839)
1. Create a new Third Person Blueprint template project
2. Create a new map, Menu
3. Set ThirdPersonGameMode to Use Seamless Travel
4. In ThirdPersonCharacter's Event Graph, set an input key to Execute Console Command: "servertravel ThirdPersonExampleMap"
5. Open the Menu map
6. PIE with Number of Players set to 2
7. Use the input key on the Server
Both Client and Server travel to the ThirdPersonExampleMap, but the Client cannot move or see its character. The camera appears to be in a different place than the character that shows up on the Server. The Server sees a character floating in falling mode. The Client can't see the Server.
New Steps for Fix Test because of [Link Removed]:
1. Follow the steps above to step 4, then close the editor
2. Launch the project in game mode
3. Bring up the console with ~ and enter "open Menu?listen"
4. Launch another game instance of the project
5. Bring up the console and enter "open 127.0.0.1"
6. Alt+Tab back to the first game instance(Server)
7. Hit "F"
8. Alt+Tab to the second instance(Client)
9. Attempt to move the character around with WASD
Head over to the existing AnswerHub thread and let us know what's up.