There was a problem parsing the package": how to fix it

What the message means

Before installing, Android reads the manifest inside the package. If it cannot, it shows There was a problem parsing the package (or There was a problem while parsing the package on newer builds). Nothing has been installed at that point.

The causes

Incomplete download. By far the most common. The file size on your phone is smaller than the size on the version page, or the download was interrupted. Download again, ideally on Wi-Fi, and check the size before opening.

Package requires a newer Android. If the manifest's minimum SDK is above your Android version, some devices report a parse error instead of a clear incompatibility message. Compare the Requires Android field on the version page with your Settings › About phone, and pick an older version if needed.

Bundle opened with the wrong installer. An .xapk or .apks file renamed to .apk is a zip archive without a manifest at the top level, so the stock installer cannot parse it. Open it with an XAPK installer instead; see the bundle formats guide.

Modified or re-signed file. Tools that strip or alter the manifest produce packages the installer rejects. Get the original file from a reliable source.

Quick checks in order

1. Compare file size with the download page.
2. Confirm the extension is .apk, not .xapk or .zip.
3. Confirm your Android version meets the minimum.
4. Re-download and try again.

Rare causes

Some manufacturers' installers fail on very large APKs (over 2 GB) or on files stored on an SD card formatted as portable storage. Copy the file to internal storage before opening. On Android 4.x devices, packages built with the modern v2 or v3 signature only can also trigger the error; nothing can be done on the phone side except choosing an older version.