I'm having the same problem on FTB Interactions
Here's the whole log
Failed to download file.
Name: forge-14.23.5.2836.jar
URL: https://s3.amazonaws.com/Minecraft.Download/versions/forge-14.23.5.2836/forge-14.23.5.2836.jar
Error details: The requested URL returned error: 403 Forbidden
Filename on disk: forge-14.23.5.2836.jar
Path: C:\Users\Daniel\Documents\Curse\Minecraft\Install\versions\forge-14.23.5.2836\forge-14.23.5.2836.jar
Exists: Nonexistent