Hi @frfvipy!
This warning indicates you have a function named wc_template_redirect hooked to an action, either in your theme or a plugin, but that function name is not available to WordPress for some reason. When that action fires, if one of the hooked functions is not available, this is the warning you get.
What you can do is, updating your theme and all of your plugins and see if that helps.
If not, change the theme to Storefront and visit your WordPress Admin Dashboard → Plugins page. Deactivate all plugins. Reactivate your theme first and check again for the warning, then enable your plugins one at a time so that you would be able to figure out which plugin is causing the issue.
While you are enabling the plugins, if the warning appears, you would be able to tell that the plugin that you just enabled is the culprit here.
When you figured out the plugin causing the issue, check whether it has any updates available. If so, update that plugin and see if it resolves the issue. If no updates are available, you could try contacting the plugin developer, reporting the bug. Or, you could try debugging and fixing the bug yourself (if you are comfortable with coding).
Cheers.
