I set up a new forge project in 1.15.2 for the first time. Copied MDK to a new folder, ran gradlew genEclipseRuns and gradlew eclipse, Imported the folder to eclipse as a java project (for the record, i tried it as a gradle project and the same thing happened) and it gave me the following error in the problems section, and nothing from forge works:
'PowerApples' is missing required library: 'C:\Users\REDACTED\Desktop\Java Workspaces\PowerApples\unresolved dependency - net.minecraftforge forge 1.15.2-31.2.31_mapped_snapshot_20200514-1.15.1'