After starting jenkins with :

docker run -d -p 49001:8080 -p 50000:50000 -v jenkins_home:/var/jenkins_home --name jenkins jenkins/jenkins:lts

 Plugins installation is failing.

Please find the screeshot below.

I am getting same error message when I change "Update Site" field in pluginManager/advanced tab to http from https.

So, I think the problem is the update-center.json file url's are http not https. (I May be Wrong, Pardon).