Added error checking

fclauncher/InstanceManager.go

@@ -501,6 +501,9 @@ func (i *InstanceManager) ImportMrpack(data io.Reader, name string) {
 		if err == io.EOF {
 			break
 		}
+		if err != nil {
+			fmt.Printf("Error unpacking modpack file: %s\n", err)
+		}
 		if entry.Name == "modrinth.index.json" {
 			i.app.Status("Loading metadata")
 			file, _ := entry.Open()