Block changes do not save in admin/structure/block/ page I have a large number of blocks in a Drupal website. Now I can not save changes in region and order of blocks in admin/structure/block/ page.

There is no message at the top of the page, no Javascript error in console and no error in the error log of my cpanel.

I have increased max_input_vars in php.ini file to 5000 or upper and checked the changes in admin/reports/status/php/ to be sure about it but still block changes does not save.

How can I get out of this problem?
From my experience, this happens when you disable the Main page content block and save the changes. After doing this, clicking save will not do anything.

The simple fix is to enable the Main page content block, you should put it back under the Content region.