“Won't install” isn't one breakdown — it's seven different ones, and each has its own cure. Below is the order worth going through them in: the things that happen most often and are quickest to check come first. Each item has one check and one action.
1. Installation from this source is not allowed
Check. Settings → Apps → the app you're opening the file from (browser, messenger, file manager) → “Install unknown apps”. On Android 8.0 and newer, the permission is granted to each app separately; on Android 7.0 and lower it's a single global toggle under “Security”.
Action. Turn it on for the app you need. A common trap: you granted it to the browser, but then opened the file from a file manager — and the file manager was never given the permission.
2. Not enough space
Check. Settings → Storage. You need a reserve of roughly two to three times the file size: besides the APK itself, the system unpacks the code and creates data.
Action. Free up space. For reference, in our catalog as of 10.09.2026: the median distributed file is 61.8 MB, 426 entries are lighter than 50 MB, but 297 are heavier than 100 MB, and the record holder weighs 391 MB. Big games like Homescapes or MARVEL Strike Force will need a free gigabyte or more. Don't delete the APK itself until installation finishes.
3. Android version is lower than required
Check. Settings → About phone → Android version. Compare it with the requirement in the app's listing.
Action. Look for something that will install. 38 apps in the catalog install on Android 5.0 and lower, 183 — on Android 6.0 and lower, 448 — on Android 7.0 and lower. The remaining 554 listings require Android 8.0 or higher. Another route is an older version of the same app: 363 listings have more than one build, and for 49 of them the previous version requires a lower Android version than the current one. The version list opens from the app page.
4. Different CPU architecture
Check. A build with native code for 64-bit ARM won't install on a 32-bit processor. In our catalog, 246 of the latest builds are compiled only for arm64-v8a, another 58 include 32-bit armeabi-v7a, and 726 contain no native code at all — for those, architecture doesn't matter.
Action. Details and a way to find out your phone's architecture are in the article “Not supported on device”.
5. The file was downloaded incompletely or is corrupted
Check. Compare the file size with the one shown in the listing, and then the SHA-256: we print it before download, on the version page.
Action. Download it again over Wi-Fi, straight from the listing. Our links live for 15 minutes — if the download dragged on longer, resuming will append an error page to the file instead of data. Don't pass the APK through archivers or “cleaners”: any change inside the package breaks the signature. More on this in “Package is invalid” and “There was a problem parsing the package”.
6. Signature conflict with the version from Google Play
Check. Is the app already on the phone and did it come from Play? Then installing over it is impossible while the signatures differ — Android remembers the key fingerprint from the first install and won't let another one through.
Action. Either update through Play, or uninstall the old version (the data will be lost — back it up first). This applies to us too: 965 of the catalog's 1030 listings carry the same certificate fingerprint — ours, because the files are reassembled from parts and signed again; 64 listings kept the publishers' original signatures. The full breakdown is in the article “App not installed”.
7. Play Protect is blocking the installation
Check. The message has a separate line about a “harmful” or “unknown” app, not just “not installed”.
Action. Deal with the source of the file, not the toggle. Turning off the scan just to install isn't worth it: if the file really did trip something, it's better to know. We run uploaded files through antivirus engines, and anything flagged as malicious is unpublished automatically.
What never helps
- “Fixers” and “installers” from the store. Android itself performs the installation; a third-party app can only open the file, and the system makes the decision.
- Changing the file extension. Renaming doesn't change the file.
- Clearing data instead of uninstalling the app. The certificate fingerprint remains, and the signature conflict isn't going anywhere.
- Installing to a memory card. Starting with Android 6, the card is either part of internal storage or removable media — apps can't be installed to it, and this has nothing to do with the installation error.
A special case is permissions. Their presence doesn't block installation: even the most sensitive ones are granted afterwards, at the app's request. For reference, the ones that appear most often in our catalog are notifications (913 builds out of 1030), writing to external storage (644) and reading from it (605); the full list of dangerous permissions is printed in the listing before download.
