Entries by Stefan Helander

High load on CPU and disk I/O every hour (Apache, MySQL and mod_pagespeed on Ubuntu)



On one of my Ubuntu servers I noticed a significant peak in CPU load (load average, LA) and disk I/O about every hour. At first, I suspected that MySQL was the cause of this, doing some houeskeeping or garbage cleaning. However, it turned out it was caused by the Apache module mod_pagespeed. The high load […]

HP Procurve MSM422 / MAP-625 clients flow the dhcp server [solved]



A client was using the HP Procurve MSM422 / MAP-625 MultiService Access Point (wifi). It was being used in a rather crowded wifi environment and the problem was the wifi clients keept reconnecting and renegotioating so often that the DHCP server was overflowed, sometimes with DHCP requests every few seconds. They had been struggling with […]

“Not a valid image” when trying to upload images in Joomla! 3.7



Error message “Not a valid image” displayed when trying to upload an image in Joomla! 3.7. The error message is displayed even though the file type being uploded (jpg or png for example) is existing as valid type in both valid file types and mime types fields. Solution: Go to System -> Global configuration -> Media […]

PrestaShop and PayPal payment error after checkout – 699 kr was paid instead of 699 kr [solved]



A client running PrestaShop 1.6.1.13 with PayPal payment module version 3.11.4 had problems after checkout of orders with an error message saying “699 kr was paid instead of 699 kr”. It turned out it was a rounding error where PrestaShop and PayPal use different methods of calculating the rounding. The solution suggested was: Go to […]

Joomla 3.7.0 error “Warning. Empty solution not allowed” when trying to save article in frontend [solution]



After upgrade to Joomla 3.7.0 an error was displayed when saving an article in the frontend. The error message was “Warning. Empty solution not allowed”. The error message is a bit confusing, not giving any real hint what it is about. It turns out it has to do with Captcha. A new feature in Joomla 3.7.0 […]

Disable Joomla! two-factor authentication



The Joomla! two-factor authentication is a great security improvement. But if you got locked out, maybe because your smartphone with the Google Authenticator installed broke down, was factory reset or the app was uninstalled – what to do? First of all, reinstall the Google Authenticator app back into your smartphone or tablet Use FTP software […]

SiteOrigin Pagebuilder and widgets not working after site move / migration [solution]



Normally when moving, mirating or deploying a WordPress site, I use the Akeeba Backup plugin for WordPress. This works excellent, also for sites built using SiteOrigin Pagebuilder and SiteOrigin widgets bundle. If, for some reason, it is not possible to use Akeeba Backup and a more traditional approach is used, like transferring the files using […]

SIP-client behind NAT disconnects incoming external call after 8-10 seconds



Scenario: a SIP server running Elastix (Asterisk and FreePBX) with SIP-clients behind NAT. Outgoing calls from the clients (which where CounterPath Xten and Siemens Gigaset C530ip, i.e. completely different brands) works well, but incoming calls are disconnected after 8-10 seconds. Googleing the problem suggests the problem is caused by a SIP REINVITE on the client side, […]

Footer widgets not displaying when using Cherry Framework 4 for WordPress



To make the footer widgets visible when using the Cherry Framework 4 template for WordPress: Under Cherry in the backend menu, select Static Area Builder In the Footer Top section, click on the Footer Sidebars In the .col-xs-*, .col-sm-*, .col-md-* and .col-lg-* select the desired widget size for each screen size (i.e. select anyting else […]