Takes several minutes when deleting files

In additon to @GoldingD post to do a test with an new catalog: I've a similar problem in the library. Rating of pictures, going from one image to another all take minutes. After creating an new catalog and exporting the whole old catalog to the new one solvesd the issue.

I think it's worth to do a test.

have you considered creating a new catalog to test?

I am using Lightroom Classic V 13.5 and many actions ar now suddenly taking a very long time to execute, eg deleting images takes a few minutes while the system "gathers information" even changing the rating of a single image takes so much longer. this is making the software almost unusable. I have my images and catalogues on an SSD drive to speed things up and its now slower than ever. IM on a iMac i5 Quad Core with 64GB of ram. 

By @neils50296960

Do you have thousands of photos all in one great big folder, not counting photos in any sub-folders?

Try to reset the preferences to the default settings by doing the following steps:

• Close Lightroom.
• Hold down [Opt]+[Shift] while restarting Lightroom.
• Overwrite the Preferences when prompted by the dialog.
• Close Lightroom.
• Restart Lightroom.

It's recommended to backup your preferences before you reset the preferences to the default settings: 

https://helpx.adobe.com/lightroom-classic/kb/preference-file-and-other-file-locations.html

What has been changed on your system before the error occur?