When checking for plugin conflicts, the first thing to do is to backup your website. In case of any error while doing any kind of maintenance to your site, you want to make sure you have a backup if anything goes wrong so your site is protected. You can safely disable plugins and themes without affecting your website, but it is always a good idea to be safe and back thing up.
Plugin Conflicts
Deactivate all of the plugins except for the one controlling your theme and any theme add-ons you’ve installed. This can be easily done by opening Bulk Actions and selecting Deactivate. After this is applied, Check your site to see if the issue still exists. If there is still a problem, you now know that a plugin wasn’t a problem and you can check the theme. If the problem is fixed, you’ll need to determine which plugin is causing the issue. Activate each plugin one by one until the error is back, at which point you’ll know which plugin is causing the problem. When you determine which plugin is causing the error, call the support team for either the plugin’s developer or Wordpress so they can help you solve the issue. They will most likely have run into the conflict before and can walk you through the solution process.
Theme Conflicts
If a plugin isn’t the problem, it may be the theme your using. To test if it’s the theme, you will have to deactivate your current theme an activate a default theme. If you are currently using a default theme (like Twentyseventeen), switch to another default that is given to you. To activate, go to Appearance » Themes and then choose one of the other themes test with. Once activated, see if the problem continues on your site. If the conflict is fixed, you now know the theme is the issue. Like the solution for plugin conflicts, make sure to contact the theme developer or Wordpress so they can help you find a solution and make sure your site is error-free!