Hey there,
First of all thanks for choosing ThemeSelection. 🤩
Well, we have tried our best to make it easy to register/log in on our site.
Although in case you are unable to do so, we can help.
The possible reason for the Sign in/login issue
Make sure you try to log in with the correct method
If you have created an account using Social login for ex: Github use the same method
If you have created an account using Sign up form then
Type the correct password (cross-check that your capslock key is not on by mistake)
Try clearing the cache first or try incognito mode.
In case you have forgotten your password follow the guide: How to recover the password?
If still you are unable to log in/register, feel free to Contact Us