It looks like a PHP memory issue or timeout.
Can you enable debugging in WordPress and see if there’s anything written to the PHP error log:
- Edit your wp-config.php
- Search for:?
define('WP_DEBUG', false);
- Replace with:?
define('WP_DEBUG', true);
- Add this line below:
define( 'WP_DEBUG_LOG', true );
Run a scan, wait only a few minutes (the scan shouldn’t take longer than that). The log (if any) will be saved to “/wp-content/debug.log”.
Also, you can try to configure the scanner to use less system resources:
1.Basic Settings:
?-File Size > Scan only files smaller than : Set it to 100kb
?-Ignore file extensions: Add the following extentions:
po,pot,mo,css,png,jpg,gif,tiff,xml,json,woff,woff2,ttf,eot,yaml,svg,txt
?
2.Advanced Users Settings:
?-File snapshot: Disable it.
?-Database snapshot: Disable it.
?-Files and folders > Warn if executable files: Disable it.
?
3.Nerds Settings
?-File integrity checksum: Select “MD5”
??
Then, try to run a new scan.
Lastly, check if the ad is really on your site or your browser: try to access the site with another browser or device. Similar issues could sometimes be due to a virus on your computer.