ERROR: Invalid or expired request.

Hello.

Sorry to hear that. This error means that we cannot get data from the database about the answer of this current captcha, or there is no such data in the database.

If you cannot log in to the site, first you need to somehow deactivate the plugin without using the dashboard. One way to do it is to use FTP (or a file manager in your hosting panel) to delete the folder of the plugin /wp-content/plugins/simple-login-captcha/. Then you will be able to login without captcha.

Now that you have access to the dashboard, if you want to help me find the problem with the plugin (so I can potentially fix it), you can again install the plugin and do some tests.

First make sure the problem is still present by trying to login from another browser (while still logged-in in this one so you have dashboard access).

If yes, one thing to try is to temporarily deactivate all other plugins, so we can check if there is a conflict between one of them and my plugin. Once you deactivate them, again try logging in with captcha from another browser to see if it is fixed.

Another thing to check is if the database table of the plugin is still present and if data is added there. One way to see the database is from phpMyAdmin in your hosting panel. To know your database name you can check the wp-config.php file (google it to know more). There should be a database table inside it called wp_slc_simple_login_captcha or possibly starting with some other prefix instead of “wp_”.

If such table is in the database, you can visit the login screen from another browser and then check if that adds a new row in the table with the correct answer in the answer column.

And another thing to try, is to activate DEBUG mode of WordPress and check if that produces an error when trying to add or get data from the database table about the captcha (try using the captcha after that to trigger the error). If there is an error it will be added in the debug.log file in wp-content folder and we can read more about it.

And tell me what you find after doing these tests.

Regards.

I disabled plugin from database, then I was able to login. That table exists as well as one record which contain the “answer”. And I am entering same value as shown in “answer” column but no luck. Enabled logs but no exception is thrown.

Interesting. So we know the database table is there, and we know we can add data to it, that is great. But we also know for sure that the request made to read it returns null since this is the only condition that generates the invalid or expired error message that you see.

Can you also confirm that the request id is correct? First visit the login page, then right click on the gray area with the answer, click inspect in the menu, and you should see this: https://i.imgur.com/zWB823U.png

Then open the database and see if the added row to the table has both the same request ID and the same answer as the ones you see on the login page.

Also by the way, when you enabled debug mode, you have to enable debug logging as well in order to add errors to the log (both WP_DEBUG and WP_DEBUG_LOG to be true).

Also have you done any changes recently like adding new plugin related to login or to security? Something that could be conflicting with the login process.