If Installation Fails:

WordPress theme installation could fail for a number of reasons.

Destination folder already exists: If the theme already exist and you try to upload the theme this error occurs. Please delete the existing theme from the server before installing a new version of the theme.

You can delete existing theme from the dashboard. For this, you need to activate a different theme. Then you can find the delete button in the theme details. You can delete the existing theme and upload the new one from the dashboard now.

Style CSS missing: If you are uploading a theme zip file which doesn’t contain the style.css file then this error can occur. It happens when you upload a wrong zip file. Please check the theme zip file that it contains the theme folder and files.

Increasing PHP Memory Limit: In some cases, hosts will set a limit on the amount of memory WordPress can use, and this can cause certain issues, like the Customizer not being able to save or even load (just shows a white screen).

There are a couple different ways to increase your memory limit.

Edit wp-config.php

The WordPress Codex has an article on this here.

Find your wp-config.php file in the root of your WordPress installation by using FTP or CPanel.

Then add this line or if already exists change it to your preferred value.

define(‘WP_MEMORY_LIMIT’, ‘128M’);

You can put any value instead of 128M based on your server capacity.

Debugging Tips:

Sometimes you can run problems like the website is broken or customizer is not loading and you’ll need to debug to know exactly what’s going on so we can fix it.

1. Deactivate all of your plugins – does the issue still exist? If not, activate each plugin one by one until the issue happens again. This way, you can pinpoint the problem plugin.

2. Turn on WP DEBUG – do any errors display on your Dashboard or on your live site?

3. If you’re getting a white screen while Customizing or somewhere else, try increasing your memory limit.

5. Check your error_log (or ask your hosting provider) – are there any big errors in there?