Failed Security Check after Register

Hey there!

I’m pretty new to Webdesign and I am currently trying to create a Website for my clothing brand that I’m setting up. I’m pretty much done, but I am struggling with something. I am using WooCommerce and the UM WooCommerce Extension. My problem is, every time I test-register on my site, after the registration form I get redirected to an error saying: “Failed security check”. The account gets created, but the user does not get redirected to the homepage as I intended.

Any idea why?