If you are having trouble logging into your WordPress admin because the page is continuously redirecting or is blank or showing an error, it is highly likely to be a problem caused by one of your WordPress plugins.
You will need to identify which plugin is causing the problem. To do that you need to rename your plugins folders one by one and trying to login to WordPress each time you rename one.
Renaming a plugin folder will deactivate the plugin. Eventually you should be able to login to WordPress, then identifying the plugin causing the problem as being the last plugin folder you renamed.
To change a plugin folder name:
► Login to cPanel
► click File Manager
► navigate to the plugins folder eg. /wp-content/plugins/
► click on a plugin folder (start from the top and work down the list)
► click Rename link at top of File Manager
► rename the folder and save
► then try to login to your WordPress again
Keep repeating this procedure for each folder until you can login to WordPress.
Also note a common problem lately has been the “woocommerce-admin” plugin. If you have that installed start by renaming that plugin folder first.
Still having problems, check your WordPress theme
If you find you are still having problems after doing the above, the issue may be with your WordPress theme. To test if your theme is causing the problem you can change your theme to the WordPress default theme Twenty Nineteen.
To change your theme via the File Manager:
► navigate to /wp-content/themes/
► rename the folder of your current theme
► WordPress will then start using the Twenty Nineteen theme (assuming you have it loaded)
If you can’t see a twentynineteen theme folder you can download it from the WordPress site then upload it to your themes folder.