PHP warning in the litespeed plugin

[06-Aug-2018 10:47:58 UTC] PHP Warning: array_merge(): Argument #1 is not an array in /home/sergiala/blog.sergialarconrecio.com/wp-content/plugins/litespeed-cache/admin/litespeed-cache-admin-settings.class.php on line 170
[06-Aug-2018 10:47:58 UTC] PHP Stack trace:
[06-Aug-2018 10:47:58 UTC] PHP 1. {main}() /home/sergiala/blog.sergialarconrecio.com/wp-admin/options.php:0
[06-Aug-2018 10:47:58 UTC] PHP 2. update_option() /home/sergiala/blog.sergialarconrecio.com/wp-admin/options.php:274
[06-Aug-2018 10:47:58 UTC] PHP 3. sanitize_option() /home/sergiala/blog.sergialarconrecio.com/wp-includes/option.php:297
[06-Aug-2018 10:47:58 UTC] PHP 4. apply_filters() /home/sergiala/blog.sergialarconrecio.com/wp-includes/formatting.php:4314
[06-Aug-2018 10:47:58 UTC] PHP 5. WP_Hook->apply_filters() /home/sergiala/blog.sergialarconrecio.com/wp-includes/plugin.php:203
[06-Aug-2018 10:47:58 UTC] PHP 6. LiteSpeed_Cache_Admin_Settings->validate_plugin_settings() /home/sergiala/blog.sergialarconrecio.com/wp-includes/class-wp-hook.php:288
[06-Aug-2018 10:47:58 UTC] PHP 7. LiteSpeed_Cache_Admin_Settings->_validate_singlesite() /home/sergiala/blog.sergialarconrecio.com/wp-content/plugins/litespeed-cache/admin/litespeed-cache-admin-settings.class.php:95
[06-Aug-2018 10:47:58 UTC] PHP 8. array_merge() /home/sergiala/blog.sergialarconrecio.com/wp-content/plugins/litespeed-cache/admin/litespeed-cache-admin-settings.class.php:170

Thanks for your report. Fixed in https://github.com/litespeedtech/lscache_wp/commit/26f5844dea228a319860cfcaaacc0401d660d1f8

I have made the modification that you tell me in the link and it works, now it does not give the error. I hope that this error is solved in the next updates so that everyone who has the problem is solved since changing the parameter works.

Yes, the fixes included in that link will be a part of the next plugin update. Glad it worked for you!