MuntashirAkon/AppManager · error · IllegalStateException

Could not create cache. Is this OS broken?

Error message

Could not create cache. Is this OS broken?

What it means

The private FileCache constructor creates <cache-path>/files on first use and throws IllegalStateException("Could not create cache. Is this OS broken?") if mkdirs() fails. It assumes cache-directory creation can only fail in a fundamentally broken environment, hiding the real cause (storage full, permission denied, path unavailable).

Source

Thrown at app/src/main/java/io/github/muntashirakon/AppManager/self/filecache/FileCache.java:54

    private final File mCacheDir;
    private final Map<Path, File> mFileCacheMap = new HashMap<>();
    private final Set<File> mFileCache = new HashSet<>();
    private final Set<File> mDirectoryCache = new HashSet<>();
    private final boolean mSessionOnly;

    private boolean mClosed = false;

    public FileCache() {
        this(true);
    }

    private FileCache(boolean sessionOnly) {
        mSessionOnly = sessionOnly;
        mCacheDir = new File(FileUtils.getCachePath(), "files");
        if (!mCacheDir.exists()) {
            if (!mCacheDir.mkdirs()) {
                throw new IllegalStateException("Could not create cache. Is this OS broken?");
            }
        }
    }

    @Override
    public void close() {
        mClosed = true;
        if (mSessionOnly) {
            deleteAll();
        }
    }

    @Override
    protected void finalize() {
        if (!mClosed) {
            close();
        }
    }

View on GitHub (pinned to 0152f468fc)

Solutions

1. Check free storage space; free space or clear the app cache so the directory can be recreated.
2. Log FileUtils.getCachePath() when mkdirs fails to identify the real cause (the boolean return hides errno).
3. Catch IllegalStateException at cache-consumer call sites and disable caching features gracefully.
4. Restart the app/runtime if the cache path is only temporarily unavailable.
5. On restricted profiles, ensure the app's cache directories are accessible or fall back to internal cache.

Example fix

// before
if (!mCacheDir.exists()) {
    if (!mCacheDir.mkdirs()) {
        throw new IllegalStateException("Could not create cache. Is this OS broken?");
    }
}
// after
if (!mCacheDir.exists() && !mCacheDir.mkdirs()) {
    File fallback = new File(ContextUtils.getContext().getCacheDir(), "files");
    if (fallback.equals(mCacheDir) || !fallback.mkdirs()) {
        throw new IllegalStateException("Could not create cache at " + mCacheDir);
    }
    mCacheDir = fallback;
}

File cacheDir = new File(FileUtils.getCachePath(), "files");
boolean ok = cacheDir.isDirectory()
        || (cacheDir.getParentFile() != null
            && cacheDir.getParentFile().canWrite()
            && cacheDir.mkdirs());
if (!ok) {
    // storage full or unwritable: disable cache-dependent features first
}

try {
    FileCache cache = FileCache.getInstance();
    // use cache
} catch (IllegalStateException e) {
    // cache unavailable: skip caching, free storage space, or clear app cache
}

When it happens

Trigger: Instantiating FileCache when the cache path returned by FileUtils.getCachePath() cannot be created: storage full, unwritable parent, cache dir unavailable in restricted users/profiles, or emulated-storage failures.

Common situations: Device storage completely full, app cache deleted with unwritable parent, multi-user/work/restricted profiles denying cache access, FUSE/emulated-storage failures on some ROMs, cloned apps in isolated profiles.

Understand the failure class

Background: mkdir permission denied (EACCES): failed to create directory errors explained — this error's family across 32 libraries.

Related errors

• Couldn't find any writable Obb dir
• Could not delete the selected backups
• Could not create package staging directory
• Could not create staging files
• Failed to access properties of the KeyStore folder.

AI-assisted analysis of MuntashirAkon/AppManager@0152f468fc (2026-09-12). Data as JSON: /api/errors/072d5d57c00d2d1c. Report an issue: GitHub.