Hi myriamloor. Here are some ways to troubleshoot your issue:
https://codex.wordpress.org/Login_Trouble
All of this suggestions are really good if I could log in, but that is the issue, I can’t
Moderator
t-p
(@t-p)
Try manually resetting your plugins (no Dashboard access required). If that resolves the issue, reactivate each one individually until you find the cause.
If that does not resolve the issue, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel, navigate to /wp-content/themes/ and rename the directory of your currently active theme. This will force the default theme to activate and hopefully rule-out a theme-specific issue (theme functions can interfere like plugins).
Firstly, you need to check the error_logs and see the errors (You may post the errors here)
Secondly, check the PHP version if Theme compatible with the PHP version.
If you still are unable to log in as it does not recognise the log in detials, the follow these
1. Go to PHPmyadmin.
2. Choose the DB (database) used for the site.
3. Go to wp_users (depending on table prefix if wp_ or whatever is used)
4. Edit the user. In the password box, place the new password and make sure that Function is MD5.
You can also visit this link for screenshots on how to do it.
https://codex.wordpress.org/Resetting_Your_Password
I had a similar issue once. I agree with Tara that the plugins might be the issue.
Also try going to your server and /wp-login.php . See if that opens. If you’re having the issue I think you might then you’ll be able to enter your info then it will give you a blank screen. Then if you go to your website you’ll see the admin bar across the top. Definitely try to reset your plugins though.
This issue can be caused by a runaway plugin that is eating up your memory. The dashboard requires much more memory than your normal page and that can cause it not to load.
