As written here,
https://wordpress.org/plugins/ablocks/
from about 10 days the plugin aBlocks is disabled from download and activation, but I can’t activate the add on “Certificates” without aBlocks.
You can check the screenshot here: https://screenrec.com/share/MRju7HGzCT .
Then I was able to download aBlocks passing trough google and I downloaded the 2.5.2 version and now I can activate the certificates..