MuntashirAkon/AppManager · error · BackupException

Failed to decrypt ${Arrays.toString(backupSourceFiles)}

Error message

Failed to decrypt ${Arrays.toString(backupSourceFiles)}

What it means

After staging the APK file placeholders, restoreApkFiles decrypts the backup's APK source files via mBackupItem.decrypt(). This error means decryption of one or more of those encrypted files threw an IOException — the encrypted data could not be read or transformed back to plaintext. It aborts the APK restoration phase.

Source

Thrown at app/src/main/java/io/github/muntashirakon/AppManager/backup/RestoreOp.java:355

            final int splitCount = mBackupMetadata.splitConfigs.length;
            String[] allApkNames = new String[splitCount + 1];
            Path[] allApks = new Path[splitCount + 1];
            try {
                Path baseApk = packageStagingDirectory.createNewFile(mBackupMetadata.apkName, null);
                allApks[0] = baseApk;
                allApkNames[0] = mBackupMetadata.apkName;
                for (int i = 1; i < allApkNames.length; ++i) {
                    allApkNames[i] = mBackupMetadata.splitConfigs[i - 1];
                    allApks[i] = packageStagingDirectory.createNewFile(allApkNames[i], null);
                }
            } catch (IOException e) {
                throw new BackupException("Could not create staging files", e);
            }
            // Decrypt sources
            try {
                backupSourceFiles = mBackupItem.decrypt(backupSourceFiles);
            } catch (IOException e) {
                throw new BackupException("Failed to decrypt " + Arrays.toString(backupSourceFiles), e);
            }
            // Extract apk files to the package staging directory
            try {
                TarUtils.extract(mBackupInfo.tarType, backupSourceFiles, packageStagingDirectory, allApkNames, null, null);
            } catch (Throwable th) {
                throw new BackupException("Failed to extract the apk file(s).", th);
            }
            // A normal update will do it now
            InstallerOptions options = InstallerOptions.getDefault();
            options.setInstallerName(mBackupMetadata.installer);
            options.setUserId(mUserId);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
                options.setInstallScenario(PackageManager.INSTALL_SCENARIO_BULK);
            }
            AtomicReference<String> status = new AtomicReference<>();
            PackageInstallerCompat packageInstaller = PackageInstallerCompat.getNewInstance();
            packageInstaller.setOnInstallListener(new PackageInstallerCompat.OnInstallListener() {
                @Override

View on GitHub (pinned to 0152f468fc)

Solutions

1. Re-download or re-copy the backup; the encrypted APK archive is likely truncated or corrupted.
2. Verify the backup was taken with a compatible AppManager version and encryption settings.
3. Check that all files in the backup item exist and are readable before decrypting.
4. Retry the restore; transient I/O errors (e.g. on external storage) can cause spurious failures.

Example fix

// before
backupSourceFiles = mBackupItem.decrypt(backupSourceFiles);
// after
for (Path f : backupSourceFiles) {
    if (f.getLength() <= 0) throw new BackupException("Encrypted file empty/corrupt: " + f);
}
backupSourceFiles = mBackupItem.decrypt(backupSourceFiles);

for (Path f : encryptedFiles) { if (!f.exists() || f.length() == 0) throw new IOException("Missing/empty encrypted file: " + f); }

try { files = backupItem.decrypt(files); } catch (IOException e) { throw new BackupException("Failed to decrypt " + Arrays.toString(files) + " — verify backup integrity and encryption settings", e); }

When it happens

Trigger: mBackupItem.decrypt(backupSourceFiles) throws IOException: encrypted APK files missing/corrupt, wrong cipher/key, truncated tar members, or I/O failure reading the encrypted files.

Common situations: Partial backup copies; encryption scheme changes between AppManager versions; key/password mismatch.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

• Couldn't delete old file <inputFile>
• Failed to write checksums.txt
• Failed to encrypt
• Master key existed when the checksum was made but now it doe
• Master key exists but it didn't exist when the backup was ma

AI-assisted analysis of MuntashirAkon/AppManager@0152f468fc (2026-09-12). Data as JSON: /api/errors/810b5630dfe0b17b. Report an issue: GitHub.