troubles activating and deactivating/deleting plugins

Hi,
I’ve read the description – this doesn’t sound like it’s caused by Shield.

What makes you think that it is caused by Shield?

Try this:

1) Verify that in this moment your site experiences the problem you’ve described:
– attempt to disable any plugin that isn’t Shield
– refresh your plugins page.
– if your site still has the problem, the plugin will still be enabled?
(hopefully I’ve understood the original problem correctly)

2) Forcefully deactivate Shield.
– Using FTP or any other file manager, rename the folder: /wp-content/plugins/wp-simple-firewall/ to /wp-content/plugins/wp-simple-firewall.bak/
– reload your WP plugins page
– you’ll get a notice to say the shield plugin was deactivated because the file couldn’t be found. At least, you should see that error notice. This is expected. If you don’t see it, then something is quite wrong with your site config.
– attempt to deactivate any other plugin as you did above in Stage 1.
– refresh. Was the plugin really deactivated?

Option 1:
Yes: it looks like Shield is somehow contributing to that bug’s behaviour.
No: Shield isn’t causing your problem.

@paultgoodchild

Hello Paul,
thank you for your answer.

I had tried this before. I encountered the option “No”. The plugins were “re”activated on refresh.

But, simply forcefully deactivating a plugin doesn’t reset the changes, the plugin had made to other settings when configuring it.
Doesn’t shield security write any changes to other files when being configured?

Shield was designed to work only when the plugin is active. You may have experienced otherwise with other security plugins, Shield is different.

So if ‘no’ then it’s definitely not Shield, sorry.

There’s also no code within Shield to “do” what you’re seeing.

@paultgoodchild

Okay, so I keep on searching …

Thank you very much for your time and support!

@paultgoodchild

Strike! I found out what caused the problem!

It was the plugin Query Monitor.

As I tried to activate an installed plugin (health check) and clicked on the option “health check” I got an error message, saying that I dont’t have the right to enter that page.
I add the message here, but it is in German:

Du bist leider nicht berechtigt, auf diese Seite zuzugreifen.
Diese Meldung wurde durch WordPress Core ausgel?st.
Aufrufstapel
    wp_die()
    wp-admin/includes/menu.php:364
Query Monitor

“Sender” was the plugin Query Monitor.

So I forcefully deactivated it (by renaming the plugin subdirectory) and … everything was fine again. I’m able again to activate/deactivate/delete plugins as usual.

I have not tested, wether it was due to settings of QM or to the plugin itself!

Great stuff! Glad you were able to find the culprit in the end!

@paultgoodchild

Ha, not finally!

It was an issue of clearing the object cache.
That solved the problem.