pages and posts are not working

HI raizaduran.

I don’t know what suddenly happened

So, the standard troubleshooting questions are:
1. When is the last time it worked correctly?
2. What has changed since then?

Here’s an article that might help:
https://www.wpbeginner.com/wp-tutorials/how-to-fix-error-too-many-redirects-issue-in-wordpress/

I had installed a plugin “redirection” but never activated that.

Could be the reason behind it?

I’m actually moving my website to a new URL, that’s under development right now.

Something changed to cause the behavior you’re seeing now. If you don’t remember exactly what it was then I’d recommend deactivating all your plugins to see if that fixes the problem. If so, reactivate them one at a time to find which one is causing the issue.

Sounds great. I’ll try to fix it up bdbrown. Thanks.