0Fixed: Deprecated PHP errors in wordpress dashboard

Earli­er today I updated our test site, in pre­par­a­tion for rolling updates out to the main site.  This involved updat­ing sev­er­al plu­gins and repla­cing the “BeforeTheDead­line” plu­gin with Jet­pack.  After com­plet­ing the updates I found I was get­ting sev­er­al error mes­sages on the dash­board, under the “incom­ing links” dash­board wid­get, and even more errors when I tried to empty the W3 Total Cache caches.

The most com­mon error was as below or sim­il­ar to below (which was the error shown on the dashboard)

Deprec­ated: Assign­ing the return value of new by ref­er­ence is deprec­ated in …/wp-includes/class-simplepie.php

I was able to clear the errors by deac­tiv­at­ing all plu­gins, and re-enabling 1 at a time to lead me to the cul­prit — an update to the “WP Auto Affil­i­ate Links” plu­gin we use to insert links to amazon for some products.  A bit more research and a com­par­is­on of the code between the old plu­gin and new ver­sion led me to a fix fairly swiftly — the plu­gin con­tains some code near the top which turns on PHP errors.

[php]error_reporting(E_ALL & ~E_NOTICE);[/php]

Remov­ing this line (or com­ment­ing it) com­pletely resolved the problem.

As a fur­ther note — these warn­ings from PHP are nor­mal for any­one run­ning word­press on an up-to-date PHP5 because word­press includes lots of leg­acy code which uses func­tions which are now deprec­ated.  The reas­on they aren’t nor­mally shown is because non fatal errors are usu­ally sup­pressed.  It’s high time word­press updated this leg­acy code, but that is a dis­cus­sion for anoth­er time.  In the mean­time — if you start to get these errors after a plu­gin update you need to check the plu­gin code and edit out any lines that include the error_reporting() func­tion call.

In the pro­cess of resolv­ing this issue I also dis­covered some­thing else quite use­ful.  When I wanted to obtain the pre­vi­ous ver­sion of the auto affil­i­ate links plu­gin I dis­covered that these are all archived on the wordpress.org down­loads page.  The cur­rent ver­sion (at time of writ­ing) is 2.3.2 which can be down­loaded from https://downloads.wordpress.org/plugin/wp-auto-affiliate-links.2.3.2.zip.  My pre­vi­ous ver­sion was 2.2.2 — so I guessed the down­load link would be https://downloads.wordpress.org/plugin/wp-auto-affiliate-links.2.2.2.zip if old ver­sions were retained.  Hey presto — using that address worked per­fectly, kudos to word­press for keep­ing old versions.