Magento 2 error when adding new customer

Hi there.
I have a Magento 2.4.1 setup that has an issue that came up out of the blue. I get an error every time I try create a new customer. The new customer gets added but i'm not redirected to the customer dashboard instead the signup form reloads with an error that says "Content must be string or resource; received "Magento\Framework\Phrase"
Refer to the screenshot.

I need that fixed.
Only apply if you have fixed such an issue and if you will be able to fix it Asap.

Thanks