Standalone Backendless 'FileSystemPreferences checkLockFile0ErrorCode' on EC2


Standalone Backendless mounted on Amazon EC2.
coderunner.log shows the following message every 30 seconds:

Apr 15, 2016 8:26:13 AM java.util.prefs.FileSystemPreferences checkLockFile0ErrorCode
WARNING: Could not lock User prefs.  Unix error code 2.
Apr 15, 2016 8:26:13 AM java.util.prefs.FileSystemPreferences syncWorld
WARNING: Couldn't flush user prefs: java.util.prefs.BackingStoreException: Couldn't get file lock.

I tried to use this solution, but it does not help.
How can I fix this?

Could you give some more information.
How does it affect on work ? Files inaccessability or some freezing during work, or something else ?

Hi Mikhai,

Does your user running the stack have full permissions for folders, in which the stack is located?

Where is the stack is located? I’ll check permission?

So far I have not noticed the problems in the work. Оnly this message every 30 seconds.

I mean the Backendless stack. By default it should be located inside /opt or /etc, but you could specify any location during the installation.

I use standard Bitnami Standalone Backendless cloud installation.

Backendless stack located inside /opt/bitnami/ with ROOT owner and 755 permissions.

Please try this answer:
After that restart all services and inform us whether you’re still getting that error.

This solution does not help

coderunner.log show:

[INFO] JDK from "JAVA_HOME" - /opt/bitnami/java
[INFO] JRE from "JRE_HOME"  - /opt/bitnami/java
[INFO] CodeRunner(tm) Backendless Debugging Utility
[INFO] Copyright(C) 2016 Backendless Corp. All rights reserved. 
[INFO] Version: 3.0.12-ENTERPRISE Build date: 20160324-0927

[WEBORB ERROR, Thread-19, 04:20:16 10:51:14] Can't parse port from amazon's user data. Will use value from config. null
Apr 20, 2016 10:51:15 AM java.util.prefs.FileSystemPreferences$1 run
WARNING: Couldn't create user preferences directory. User preferences are unusable.
Apr 20, 2016 10:51:15 AM java.util.prefs.FileSystemPreferences$1 run
WARNING: No such file or directory

Could you try to update to the latest version of Standalone, which is 3.0.0-24? You can get it on Bitnami’s website:

I launched a new server based on Backendless 3.0.0-24, and the problem persists.
This message appears after the first request to the Hosted Service.

How did you install Standalone on Amazon EC2?

I’m use Amazon Machine Images, version Standalone Backendless 3.0.0-24 (64-bit), HVM -> ami-61f9e40b