BuddyPress.org

When sending a private message an error is displayed “Message was not sent. Please try again.” while the message is actually delivered and also in the Sent items. Sending a public message does however not show the same behaviour.

I have tried using the 2015 theme (running default 2011) and disabling all other plugins, but to no improvement.
One odd thing about my setup is that I have sqlite as backend DB.

Hope someone can point me in the right direction on how to troubleshoot / fix this.

About my set-up:
1. Which version of WordPress are you running?
WordPress 4.5.2 running Twenty Eleven theme.

2. Did you install WordPress as a directory or subdomain install?
Directory

3. If a directory install, is it in root or in a subdirectory?
Root

4. Did you upgrade from a previous version of WordPress? If so, from which version?
Nothing major just roling updates for CentOS

5. Was WordPress functioning properly before installing/upgrading BuddyPress (BP)? e.g. permalinks, creating a new post, commenting.
yes

6. Which version of BP are you running?
2.5.3

7. Did you upgraded from a previous version of BP? If so, from which version?
No

8. Do you have any plugins other than BuddyPress installed and activated? If so, which ones?

• BP Registration Options
• BuddyPress Members only
• CloudFlare
• Contact Form 7
• Contact Form 7 – Dynamic Text Extension
• Google Analytics Dashboard for WP
• Nav Menu Roles
• Social Media Feather
• SQLite Integration
• UpdraftPlus – Backup/Restore
• WP Easy Paypal Payment Accept
• WP reCaptcha Integration
• WP-Ban
• WP-Mail-SMTP
• WP-Polls

9. Are you using the standard WordPress theme or customized theme?
Twenty Eleven theme

10. Have you modified the core files in any way?
No

11. Do you have any custom functions in bp-custom.php?
No

12. If running bbPress, which version? Or did your BuddyPress install come with a copy of bbPress built-in?
n/a

13. Please provide a list of any errors in your server’s log files.
Don’t see any

14. Which company provides your hosting?
AWS

15. Is your server running Windows, or if Linux; Apache, nginx or something else?
CentOS 7 with Apache