Admin page is missing

I was trying to install a new shipping module - Tiki shipping; and not sure what happened, now my admin page is missing. Everytime I try to log in, it will re-route me to a page that does not exist.

https://www.wdcharacters.com/zencart/admin --- reroutes to https://www.wdcharacters.com

I have tried to undo my shipping module installation, but it's still not working. Can someone help?

Also, now when I try to checkout from the cart, when it comes to the shipping page, it shows up blank.

https://www.wdcharacters.com/zencart

What should I do?

Have you installed much or many mods?

If not re upload your admin folder.

Of course do a back up first!

admin page is no longer missing. But, my shipping page is still blank.

Anybody knows how to fix this?

Look for the support page for the shipping module you installed and post your question there.
This area will be visited by the Mod creators and others using the mod.