"Save Current As" is not fully loading the newly-saved level

Workaround:
Navigate to and open the newly-created level in the Content Browser prior to LaunchOn.

After using the Save Current As tool, Game runs into error when trying to LaunchOn. Editor displays a Warning about level not being fully loaded.

I encountered the following error during cook for LaunchOn to Windows:

CookResults:Warning: Warning Package /Game/New supposed to be fully loaded but isn't. RF_WasLoaded is set
LogCook:Warning: Package /Game/New supposed to be fully loaded but isn't. RF_WasLoaded is set
CookResults:Warning: Warning Package /Game/New supposed to be fully loaded but isn't. RF_WasLoaded is set
LogCook:Warning: Package /Game/New supposed to be fully loaded but isn't. RF_WasLoaded is set
CookResults:Warning: Warning Package /Game/New supposed to be fully loaded but isn't. RF_WasLoaded is set
LogCook:Warning: Package /Game/New supposed to be fully loaded but isn't. RF_WasLoaded is set
CookResults:Error: Error Unable to cook package for platform because it is unable to be loaded: D:/Engine/GameDevProjects/MyProject4/Saved/EditorCooked/WindowsNoEditor/MyProject4/Content/New.umap

This issue is observed occurring in the current 4.15.1 Binary CL: 3347183

This issue does not occur in 4.14.3

Regression:
Working: UE4/Main, CL 3206910
Broken: UE4/Main, CL 3206922

1. Create a New Blueprint Project (type doesn't matter)
2. Save your current Level. File>Save Current As
   • Name it "NewMap" (save Path and Name do not matter)
3. Click Save
4. Select File > Save Current As
   • Name the new level NewMap1
5. Press the down arrow to the right of the Launch button
   • Select your Device (Windows)
6. A Save Content prompt will appear, click Save Selected

Result:
I experienced an error during the LaunchOn Cook and the LaunchOn window crashed.

Expected Result:
LaunchOn should complete successfully without errors or crashing.

Frequency:
5/5