guides not showing up in Illustrator

Maybe View > Trim View is selected as is suggested in this thread:

https://community.adobe.com/t5/illustrator/guides-greyed-out/m-p/11132448/thread-id/176987?page=1#M177001

If you drag from the intersection of the rulers, you will see faint lines that will disappear when you let go.

That is because you do not drag guides, but reset the X/Y 0/0 point.

Dragging from somewhere inside a ruler should give a guide.

Hi Katherine,

Sorry to hear about your experience. There has been no change in the behavior of the guides in recent versions. Would you mind sharing more details like:

1. Version of OS and Illustrator.

2. Is it happening with a specific document or all?

3. Have you tried resetting preferences? If not, please try that by following the steps provided on help article 

 https://helpx.adobe.com/illustrator/using/setting-preferences.html#setting_illustrator_preferences and let us know if it helps.

**Please note that resetting preferences will remove all the custom settings and Illustrator will launch with default settings. You can also take a backup of the folders in case you want to. Location is mentioned in the article. 

All this information would help us understand your issue. Looking forward to your response.

Regards,

Ashutosh