Yes. I've read all other questions regarding this problem. Like this one:
Error 504 when downloading apps from Play Store?
It's the same problem as this one but with more background information and an other app:
How to fix installation error -504?

The details:
My device is an Ulefone Be Touch 2 running Android 5.0.

My connection is perfect. To be sure I tried different networks, among them are 3G, 4G and wifi on ADSL, VDSL, cable and fiber. I've also used Tor and 3 different VPN providers in 3 countries on 2 continents. Let's say I ruled the network out.

  • A single app does not install: OpenKeychain.
  • Currently I have 126 apps installed.
  • It does not install via desktop browser > play store > install button.
  • I have enough free space (40GB). The app is 7MB.
  • Re-adding Google account and clearing caches did not work.
  • Even a complete device wipe and re-install didn't work.
  • Downloaded the apk and tried manual installation, same error.

I also own a Nexus 7 (2013 wifi) and the app installs fine on that device.

  • 1) put the device in airplane mode for ~60 seconds, then reboot, turn off airplane mode, download again. OR TRY 2) turn off data/wifi for ~90 seconds, then turn back on, download again. ///you can also sideload the app. ///If the choices (1 or 2) help let me know and I'll post as an answer. ///Did you force stop apps before clearing data??
    – HasH_BrowN
    Commented Sep 17, 2015 at 3:15
  • The more I read about it and reread what you wrote, I'm thinking you have an issue with your ROM.
    – HasH_BrowN
    Commented Sep 17, 2015 at 3:17

2 Answers 2


I think this is a bug in Lollipop, I found this on another app forum:

I’m getting the Error Code -504 (INSTALL_FAILED_UID_CHANGED) when installing App from Google Play

Try to erase the “/data/data/appnamespace” directory on your device and try again. This is a “bug” Android 5.0 Lollipop developer preview which was fixed in the final release version.

That (plus a reboot, remove + reinstall of the app and remove + replace of my google account) fixed this issue for me.

It definitely isn't a connectivity issue, and it's nothing to do with a 504 HTTP error.

  • I'm not sure that the namespace directory is for this app. I've tried to remove com.android.keychain and that didn't change anything.
    – Thijs
    Commented Oct 5, 2015 at 11:09
  • @Thijs I think they can change directories so it may be somewhere else
    – Keith
    Commented Oct 5, 2015 at 11:12

This is what worked for me:

1) Clear data/cache for for the following apps:

  • Google Play Store
  • Google Play Services
  • Download Manager
  • Google Services Framework
  • Google app
  • Chrome

2) Restart the device

3) Change time and date, then back to the actual time and date.

Source: https://www.asus.com/zentalk/thread-50875-5-1.html

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