None of these suggestions worked for me. What did was modifying the .uproject file and adding the project Modules element:
{
"FileVersion": 3,
"EngineAssociation": "4.27",
"Category": "",
"Description": "",
"Modules": [
{
"Name": "MyProject",
"Type": "Runtime",
"LoadingPhase": "Default",
"AdditionalDependencies": [
"Engine"
]
}
]
}
You can just open up the .uproject file in a text editor and add the Modules element, just make sure you replace MyProject with the name of your project.