There are several possible causes for this issue: Firewall and/or antivirus software may block Overwolf/the CurseForge app, and thus prevent them from connecting to CurseForge's servers. Please check your firewall/antivirus software and unblock/provide permissions accordingly.Where to download Minecraft modpacks?
The best place for downloading modpacks is the Official Minecraft Forum. You can also find safe options at PlanetMinecraft, CurseForge, or TechnicPack. Once you have downloaded the Modpack, you need to install it to begin playing.