Explanation
Juniper ATP Cloud profiles let you define which files to send to the cloud for inspection. You can group types of files to be scanned together (such as.tar,.exe, and.java) under a common name and create multiple profiles based on the content you want scanned. Then enter the profile names on eligible SRX Series devices to apply them1. To update a custom profile, you can use the ATP Cloud Ul and navigate to Configure > File Inspection Management > Profiles. There you can edit the existing profile and change the scan limit for executable files to 30 MB, while keeping the scan limit for other files at 10 MB. This way, you can scan larger executable files without increasing the scan time for other file types. References: File Inspection Profiles Overview

Explanation
AppFW and APPID are two application security features that can be used to block malicious applications regardless of the port number being used. AppFW provides policy-based enforcement and control on traffic based on application signatures. By using AppFW, you can block any application traffic not sanctioned by the enterprise. APPID identifies applications based on their behavior and characteristics, regardless of port, protocol, or encryption method. By using APPID, you can classify applications and apply appropriate security policies to them123 References:
AppSecure: Application Visibility and Control Solution Brief
Application Firewall | Junos OS | Juniper Networks
Security Policy Applications and Application Sets | Junos OS | Juniper Networks

The error message indicates that the Junos-http application is not defined, so you need to either create a custom application or modify the security policy to use the built-in Junos-http application.
Doing either of these will allow you to successfully commit the configuration.

Explanation
AppTrack: Tracks and reports applications passing through
the device.
* Intrusion Detection and Prevention (IDP): Applies
appropriate attack objects to applications running on
nonstandard ports. Application identification improves IDP
performance by narrowing the scope of attack signatures
for applications without decoders.
* AppFW: Implements an application firewall using
application-based rules.
* AppQoS: Provides quality-of-service (QoS) prioritization
based on application awareness
The AppSecure AppTrack service module is a logging and reporting tool used to share information about application visibility. Once AppID identifies an application, AppTrack notonly monitors and records its usage, it also sends regular application activity update messages. Since these messages are sent by syslog, they can be read by any compatible third-party device, including Juniper Networks JSA Series Secure Analytics Appliances and Contrail Service Orchestration.https://www.juniper.net/content/dam/www/assets/solution-briefs/us/en/appsecure-application-visib