If you want to choose the right software for your specific device, tell me: What is your ?

Which of the three types of files listed above are you currently trying to open or extract? How to extract or unpack a Unisoc / Spreadtrum .pac file

: They ensure internal company traffic stays local while external traffic goes through a proxy.

: Only download APK utilities and firmware files from reputable, verified development sources. Malicious firmware utilities can inject malware or spy applications into extracted images.

Are you extracting a or fetching it from a live network URL ? Does your device have root access ?

If you are using an "exclusive" APK (such as Pac File Extractor or similar dumper tools), follow these general steps:

pac file extractor apk exclusive
pac file extractor apk exclusive
Legal access to free sheet music