What causes "Could not create cache. Is this OS broken?" in MuntashirAkon/AppManager?

Check available storage and free space on the device

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

ImageFileCache's constructor creates the cache directory <cache>/images via mkdirs() and throws IllegalStateException if creation fails. Since File.mkdirs() only fails on real OS-level problems (no permissions, filesystem full/read-only), the message rhetorically asks if the OS is broken. It effectively signals an unrecoverable environment failure at init time.

Source

Thrown at app/src/main/java/io/github/muntashirakon/AppManager/self/imagecache/ImageFileCache.java:33

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import io.github.muntashirakon.AppManager.logs.Log;
import io.github.muntashirakon.AppManager.utils.FileUtils;
import io.github.muntashirakon.AppManager.utils.UIUtils;
import io.github.muntashirakon.io.IoUtils;

class ImageFileCache {
    private static final long sLastModifiedDate = System.currentTimeMillis() - 604_800_000;

    private final File mCacheDir;

    public ImageFileCache() {
        mCacheDir = new File(FileUtils.getCachePath(), "images");
        if (!mCacheDir.exists()) {
            if (!mCacheDir.mkdirs()) {
                throw new IllegalStateException("Could not create cache. Is this OS broken?");
            }
        }
    }

    public void putImage(@NonNull String name, @NonNull InputStream inputStream) throws IOException {
        File iconFile = getImageFile(name);
        try (OutputStream os = new FileOutputStream(iconFile)) {
            IoUtils.copy(inputStream, os);
        }
    }

    public void putImage(@NonNull String name, @NonNull Drawable drawable) throws IOException {
        putImage(name, UIUtils.getBitmapFromDrawable(drawable));
    }

    public void putImage(@NonNull String name, @NonNull Bitmap bitmap) throws IOException {
        File iconFile = getImageFile(name);
        try (OutputStream os = new FileOutputStream(iconFile)) {

View on GitHub (pinned to 0152f468fc)

Solutions

Check available storage and free space on the device
Verify Environment/Context cache path is writable before constructing ImageFileCache
Reboot or clear app data to reset cache directory permissions
Catch the IllegalStateException and disable image caching as a fallback

Example fix

// before
ImageFileCache cache = new ImageFileCache();
// after
ImageFileCache cache;
try {
    cache = new ImageFileCache();
} catch (IllegalStateException e) {
    cache = null; // proceed without image caching
}

Defensive patterns

Strategy: try-catch

Validate before calling

File cacheDir = new File(FileUtils.getCachePath(), "images");
if (!cacheDir.isDirectory() && !cacheDir.mkdirs()) {
    throw new IllegalStateException("Cache dir not creatable: " + cacheDir);
}

Try / catch

try {
    ImageFileCache cache = new ImageFileCache();
} catch (IllegalStateException e) {
    // disable icon caching / show degraded mode
}

Prevention

Verify cache path exists and is writable before first use
Monitor device free space and degrade gracefully when low
Catch constructor exceptions at app startup and disable caching instead of crashing
Treat cache dirs as optional: always guard writes to them

When it happens

Trigger: Constructing ImageFileCache when Context.getCacheDir()/getCachePath() cannot be created or written: read-only filesystem, missing storage permissions, parent path inaccessible, or cache path malformed.

Common situations: Device storage full or mounted read-only (e.g. after USB access on some devices); running on a locked-down/emulated environment; custom ROM with broken cache-dir permissions.

Related errors

AI-assisted analysis of MuntashirAkon/AppManager@0152f468fc (2026-09-12). Data as JSON: /api/errors/353add3d9b04eec3. Report an issue: GitHub.