MuntashirAkon/AppManager · error · IllegalArgumentException

Invalid type + type

Error message

Invalid type + type

What it means

VirtualFileSystem.getNewInstance maps a registered filesystem TYPE string ('apk', 'dex', ...) to a concrete VirtualFileSystem subclass. When called with a type string no factory branch matches, it throws IllegalArgumentException("Invalid type " + type). Callers pass the type taken from MountOptions or persistence, so this indicates a type the current build cannot instantiate.

Source

Thrown at app/src/main/java/io/github/muntashirakon/io/fs/VirtualFileSystem.java:127

        return new Uri.Builder()
                .scheme(SCHEME)
                .authority(String.valueOf(fsId))
                .path(path != null ? path : File.separator)
                .build();
    }

    @NonNull
    private static VirtualFileSystem getNewInstance(@NonNull Path file, @NonNull String type) {
        if (ZipFileSystem.TYPE.equals(type)) {
            return new ZipFileSystem(file);
        }
        if (ApkFileSystem.TYPE.equals(type)) {
            return new ApkFileSystem(file);
        }
        if (DexFileSystem.TYPE.equals(type)) {
            return new DexFileSystem(file);
        }
        throw new IllegalArgumentException("Invalid type " + type);
    }

    private static final SparseArrayCompat<VirtualFileSystem> sFileSystems = new SparseArrayCompat<>(3);
    private static final HashMap<Uri, Integer> sUriVfsIdsMap = new HashMap<>(3);
    private static final HashMap<Uri, List<Integer>> sParentUriVfsIdsMap = new HashMap<>(3);

    @WorkerThread
    public static int mount(@NonNull Uri mountPoint, @NonNull Path file, @NonNull String type) throws IOException {
        return mount(mountPoint, file, type, new MountOptions.Builder().build());
    }

    @WorkerThread
    public static int mount(@NonNull Uri mountPoint,
                            @NonNull Path file,
                            @NonNull String type,
                            @NonNull MountOptions options)
            throws IOException {
        return mount(mountPoint, getNewInstance(file, type), options);

View on GitHub (pinned to 0152f468fc)

Solutions

1. Use the exact TYPE constants (ApkFileSystem.TYPE / DexFileSystem.TYPE) rather than literal strings.
2. Validate the options' type against the supported set before mounting.
3. Fix persisted/saved mount metadata to a type supported by the installed app version.
4. Catch IllegalArgumentException and surface the supported type list to the user.

Example fix

// before
new MountOptions().setType("zip");
// after
String type = ApkFileSystem.TYPE; // or DexFileSystem.TYPE
if (!type.equals(ApkFileSystem.TYPE) && !type.equals(DexFileSystem.TYPE)) throw new IllegalArgumentException(type);
new MountOptions().setType(type);

Set<String> supported = Set.of(ApkFileSystem.TYPE, DexFileSystem.TYPE);
if (!supported.contains(options.getType())) throw new IllegalArgumentException("Unsupported VFS type: " + options.getType());

try {
    VirtualFileSystem.mount(mountPoint, options);
} catch (IllegalArgumentException e) {
    // fall back to a supported type or report supported types
}

When it happens

Trigger: Calling VirtualFileSystem.mount with MountOptions whose filesystem type string is misspelled, from a newer/older app version that introduced or removed a VFS type, or persisted metadata referencing an unregistered type.

Common situations: Restoring saved mount configurations after an app update that renamed a type constant; hand-written mount scripts using a wrong type string; plugin/pro-guard stripping of a filesystem class.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• Couldn't find any writable Obb dir
• Invalid export type: {exportType}
• Could not delete the selected backups
• Could not create package staging directory
• Could not create staging files

AI-assisted analysis of MuntashirAkon/AppManager@0152f468fc (2026-09-12). Data as JSON: /api/errors/7c4409814f20eab1. Report an issue: GitHub.