Trouble Signing Into Spirters Resource on a Specific PC

[VGTurtle]

Hi.
I really need help on something.
For whatever reason, I can't sign in onto any of the Resources sites (Spriters, Models, Textures, and Sounds) on this MacBook Pro I have (I can sign in just fine on other devices, just not this specific computer).
Whenever I try to click "Login" on these sites, it always goes to a blue background with white text saying "Click here to return to the site you logged in from." and just redirects back to the home page without even logging in at all.
Is there a possible cause for this and is there any way I can fix it?

[Petie]

There are pretty much only two causes for this issue - ad blockers and outdated cookies. The first thing to try is to just clear your cache and cookies and see if that fixes it. If you have an ad blocker, disabling or removing it might help as well.