Error on add plugins page after update.

Sounds like an incompatible plugin, try disabling them one by one until the error resolves.

Theme issue, do the same for the theme. Activate a default WP theme and see if the problem resolves. If it is your theme contact the theme developer for an update.

I have the same error after updating to 4.9. I migrated back to 4.8.3 meanwhile.

• This reply was modified 8 years, 7 months ago by florinb1.
• This reply was modified 8 years, 7 months ago by florinb1.

Hi,
Got the same issue here.
tried all the above – with regards to the plugin – I don’t really know how to use
it, if anyone can tell how.

Thanks!

Got it. Actually, the problem is that “Quick Adsense Plugin” 1st rename Plugin files from host file manager then remove the Quick Adsense folder and then active. Fixed

I had the same issue,
Preoblem solved for me.

Removed all transients via the Litespeed Cache plugin, error is gone.

Fixed it by disabling

define( ‘WP_DEBUG’, true );
define( ‘WP_DEBUG_LOG’, true );

in my wp-config.php.