What “Problem Parsing the Package” Means
Android could not process the package as a valid install for the current environment. That can be caused by a damaged download, a newer minimum Android requirement, a split-package format or a package that was altered incorrectly.
Re-download Before Changing Settings
Download a clean copy and compare its size or checksum. If the new copy still fails, check Android version and package format. Disabling security controls does not repair a corrupted APK.
Split Packages
Files such as APKS or XAPK can contain multiple APK components or additional data. A standard single-APK installer may not understand them. Use a compatible installer only when the source and package are trusted.
Renaming the File Will Not Fix It
Changing .xapk to .apk, or renaming a damaged file, does not change the package structure. Identify the real format first. If it is supposed to be one APK, a parse error after a fresh download points back to compatibility or file integrity.
When to Stop Troubleshooting
If the package came from an unknown mirror, has no matching checksum, and still fails after a clean download on a compatible Android version, replacing security settings with trial and error is not a sensible next step. Use a source you can verify instead.
Check Whether the File Is Really an APK
A file can carry an APK-looking name while actually being a bundle, archive or incomplete transfer. Compare the extension, expected file size and package format before assuming Android itself is at fault. Renaming an XAPK, APKS or ZIP file to APK does not convert its internal structure.
Older Android Versions Can Be the Limit
A parser error can occur before the normal installer has a chance to explain compatibility. If the same complete file works on a newer device, compare the minimum Android level for that build with the phone that failed.