Switched On Tech Design

Category: Troubleshooting

  • WooCommerce Variable Products all showing out of stock: Sorry, this product is unavailable. Please choose a different combination.

    I must have spent hours today trying to fix a problem with Woocommerce – no matter which way I set up a variable product it always showed as out of stock no matter which combination of options I selected. The error message was:

     

    Sorry, this product is unavailable. Please choose a different combination.

     

    Very frustrating. The problem in the end? I had not yet set prices for all of the variable products. To resolve this go to Product -> Variations -> click on the dropdown box which defaults to “Add Variation” -> Set Regular Prices -> click Go.

     

    Hopefully that’s all it takes to fix your problem too. I was installing custom PHP snippets to try and resolve this issue and going down all sorts of wrong paths when I had simply neglected to take note of which fields were required.

  • PHP contact form returns 504 gateway error after moving to Digital Ocean

    This one had me scratching my head for a while – using php7.0-fpm and the latest nginx on Debian 8 Jessie I was seeing our PHP contact form working correctly but returning a Gateway 504 error upon submission, which was resulting in a great deal of resubmitted forms and error notifications from users.

     

    This only started occuring after we moved our site to Digital Ocean – it turns out that it was a IP priority issue and the following resolved it:

     

    vim /etc/gai.conf

     

    and uncommenting the following line:

     

    precedence ::ffff:0:0/96  100

    Then a reboot. Voila, the contact form worked properly again.

  • Checking whether nginx cache is working

    Just set up nginx caching and wondering whether it’s working properly? You can check it pretty easily:

     

    curl -I URL.goes.here

    That should return a bunch of information, but the important bit is:

    X-Proxy-Cache: MISS

     

    Well, in this case it’s not working. If it’s working you’ll see a HIT there.

  • Adobe Photoshop Lightroom 5.7 and Mac OS X – will no longer open

    After upgrading Lightroom 5.6 to 5.7, it refused to open with the error:

      Library not loaded: @executable_path/../Frameworks/asneu.framework/versions/a/asneu

     

    This problem stems from the fact that the system drive is a case sensitive file system; in a similar vein, we were recently unable to install Adobe CC on a similar system as it is also incompatible with a case sensitive file system. We fixed our Lightroom issue by changing the path from:

     

    /Applications/Adobe Photoshop Lightroom 5.app/Contents/Frameworks/asneu.framework/Versions/A

     

    to:

     

    /Applications/Adobe Photoshop Lightroom 5.app/Contents/Frameworks/asneu.framework/versions/a

     

    The above assumes a normal install to the /Applications directory. If you are game to try the change yourself, you make the change via Terminal:

     

    cd /Applications/Adobe\ Photoshop\ Lightroom\ 5.app/Contents/Frameworks/asneu.framework

    sudo mv Versions versions

    cd versions

    sudo mv A a

     

    Now try and start Lightroom and you should be successful.

  • ZFS: zpool replace returns error: cannot replace, devices have different sector alignment

    Trying to replace a failed SSD in a zpool we encountered the following error:

     

    cannot replace 4233944908106055 with ata-INTEL_SSDSC2BW240A4_CVD02KY2403GN: devices have different sector alignment

     

    The pool was aligned to 4k sectors – e.g. ashift=12 – whereas the new SSD was aligned to 512b sectors. There’s a quick and easy fix to this – no need to use partitioning tools:

     

    (more…)

  • ZFS on Linux: Zpool import failed

    We upgraded a Proxmox box today which was running ZFS and ran into this rather scary looking error:

     

    zpool: ../../lib/libzfs/libzfs_import.c:356: Assertion `nvlist_lookup_uint64(zhp->zpool_config, ZPOOL_CONFIG_POOL_GUID, &theguid) == 0′ failed.

     

    Zpools would not import and zpool status did not work. Resolved (so far, anyhow, still testing) by running:

     

    apt-get install zfsutils

     

    Another good reason to have test environments…

  • How to reset a user password in Windows without knowing the original password

     

    Today we were asked how to reset a Windows user password (in this case the administrator account for a Windows Home Server 2011 install) without knowing the original password. The user had a logged-in Administrator session but had typo’d their password twice successfully during the install and was not keen on reinstalling then repeating the several hours of setup they had just completed.

     

    If this happens to you, open up a CMD window with Administrator privileges (in the WHS 2011 example the CMD window automatically has these) and type the following:

     

    net user [username] *

     

    In this case:

     

    net user administrator *

     

    You will be prompted to enter a new password without having to provide the existing password first. To get a list of the users on the system, you can run:

     

    net users

     

    Use this for good, not evil!

  • Mozilla Firefox: Arrow keys move cursor within the wepage, rather than scrolling. How to fix?

     

    This one seems to be a common issue that people with children and pets encounter; a button-mashing session between said small being and the keyboard can sometimes leave your browser moving a cursor around the webpage when you press the arrow keys, instead of the keys scrolling the webpage up and down. Fortunately it’s an easy fix – it’s a selectable mode called caret browsing mode. Caret is another name for the cursor you see!

     

    To enter or exit caret browsing mode, hit F7. That should resolve this issue straight away.

  • Mediawiki 403 forbidden errors after upgrading to Ubuntu 13.10

     

    A customer upgraded from 13.04 to 13.10 and their internal wiki was broken afterwards; for a simple Apache install where the wiki was installed at the web root and all access was via the LAN (thus they were happy with not restricting the access), the fix was to add:

     

    <Location />

    Require all granted

    </Location>

     

    towards the bottom of:

     

    /etc/apache2/sites-enabled/000-default.conf

     

    …just above the last line, which should be </VirtualHost>.

    Restart apache with:

     

    service apache2 restart

     

    After that you should be able to refresh and see your wiki as before.

  • XenServer 6.2: NICs showing as disconnected despite being connected

     

    Sometimes if you connect a network cable to a NIC XenServer doesn’t register it and keeps the status as disconnected; if this happens, try the following via SSH (or from the console, though you will be kicked out of XenCenter once you do it):

     

    xe-toolstack-restart

     

    It may take a little while for the restart to finish but once it does the NIC should be showing the correct status.