Seems there is a number of new people having issues with the Store Locator Plus® address lookup feature due to a failed REST API request. With Store Locator Plus 5 all address lookups are routed back through the WordPress site via the REST API in order to protect Google API keys.
If your site is running WordPress from a subdirectory you may run into issues if your web server is not configured to properly handle REST API routing. Especially if the site is using “pretty permalinks”, any Permalink setting under WordPress Settings | Permalinks other than “plain”.
The problem is that most of the Codex articles on the subject of doing a “WordPress in it’s own directory” installs came out well before the REST API existed. Most, dare we say ALL, have not been updated since and completely ignore the corner case of a WordPress subdirectory install with Permalinks enabled.
If you have recently ported a WordPress site from another server or from a staging site to a production site and the address lookup in Store Locator Plus is failing — you may have an incomplete port. There are a few simple ways to tell that the WordPress configuration is incorrect. This video for our WordPress folks will help you determine if your “ported configuration” is the culprit.
Thankfully our MySLP users never have to deal with this sort of issue — but for our WordPress users that may have an incorrectly ported site, watch this:
WordPress 4.9.9 as well as 5.0.1 and ALL the “security patch releases” back to 3.7 now have a new CSV file management bug. Any CSV file that is uploaded is rejected by WordPress due to a security violation.
The Quick Fix
Add this to your wp-config.php file:
Yes, this will effectively disable all those cool new “security features” in the latest release of WordPress but it also will get your CSV imports working again. Just remember to take this out when WordPress 4.9.10 (or 5.0.2) comes out — assuming they deem this new “security feature” a bug and patch it accordingly.