Please report here if ads have stopped appearing on your site

Question

[Updated: 19 February 2020]
 
This is an old thread. Please start your own thread in the community to discuss your issue / problem: https://support.google.com/adsense/thread/new.
 
[Updated: 31 May 2019]
 
If ads on your sites have stopped showing on or around 24 May 2019, please read AdSensePro Frank's response at https://support.google.com/adsense/thread/6825406?msgid=7121345.
 
Google is continually investing in measures to protect and improve the experience for our advertisers, publishers, and users.
 
As we launch improvements to our systems and defenses, sites with invalid traffic may experience limited ad-serving. Additionally, if we are unable to verify the quality of your traffic, we may limit or disable your ad serving.
 
Please check out our help center on Invalid Traffic to learn about how to prevent invalid traffic and improve your traffic quality.

[Original post]
 
There have been multiple reports by publishers about ads ceasing to appear on their sites without any notification. It certainly seems as if a large number of publishers are affected, however the cause remains unclear.
 
It would be helpful if you could post here so that the scale and nature of the issue can be discussed. Please share information such as your site's address and any observations you may have.

wasaweb · Accepted Answer

This is an old thread. Please start your own thread in the community to discuss your issue / problem: https://support.google.com/adsense/thread/new.

busterjet · Accepted Answer

There has been no further communication from AdSense on this issue.
All I can suggest is that people carefully check their site's traffic sources. Traffic from social media links, link exchanges, traffic exchanges, email lists ... all could be considered poor quality. If your sites get little genuine traffic from search engines the problem is magnified further.
See also: https://support.google.com/adsense/answer/16737 - read all the information, not just that one page, but all the other pages in that entire section.

AdSensePro Frank · Accepted Answer

Google is continually investing in measures to protect and improve the experience for our advertisers, publishers, and users. 
As we launch improvements to our systems and defenses, sites with invalid traffic may experience limited ad-serving. Additionally, if we are unable to verify the quality of your traffic, we may limit or disable your ad serving.
Please check out our help center on Invalid Traffic to learn about how to prevent invalid traffic and improve your traffic quality.