In the documentation of the Jenkins "Gerrit Trigger" plugin is written that is needed the following configuration in Gerrit:
Gerrit web interface > People > Create New Group : "Event Streaming
Users". Add your jenkins user.
Admin > Projects > All-Projects > Access > Edit Global Capabilities
Stream Events: ALLOW for Event Streaming Users
Code Review - Error
Unable to create new object: /home/gerrit2/gerrit-github-installation/git/All-Projects.git/objects/4c/3f6c52b57811228a96b41469517040487bb7b
First of all: check if you are a Gerrit administrator, only administrators can change the access permissions of the All-Projects project. If you are not an administrator, ask to someone to do this for you.
Then: check which user executes the GerritCodeReview process (ps -elf | grep GerritCodeReview) and if this user has permission to create files in /home/gerrit2/gerrit-github-installation/git/All-Projects.git/objects. If something is wrong, adjust the filesystem permission accordingly (chown or/and chmod commands).