Log serialization warning stopping game from loading

When trying to open a packaged game, the engine sometimes gets stuck and stays on a black screen. When the game successfully loads into the main menu, only one of these warnings are shown in the log file, when it fails the warning is shown repeatedly until closed and it seems as thought it is stuck on loading this asset. I can’t really find any info on the forums or on here as to why this only sometimes causes a problem.

[2018.08.30-20.43.50:509] 0]LogSerialization: Warning: Waiting for …/…/…/EOTBX/Content/UI/Menu/MenuBgLeft.uasset bulk data (371904) to be loaded longer than 1000ms