If you've upgraded OpenALPR, but later need to roll it back, the procedure is described below.
First find the previous version that you wish to rollback to on this page:
http://doc.openalpr.com/release_notes.html
Windows:
You can simply download the old installer and reinstall over-top. After restarting services, the old version will be running.
Linux:
First uninstall the current version of OpenALPR. Using apt-get remove will leave configuration files, so you will not need to recreate them.
dpkg -l | grep -E '(alpr|rollingdb|vehicleclassifier)' | awk '{print $2;}' | xargs sudo apt-get remove -y && sudo apt-get autoremove -y
Next, install the previous version. Find the "Archived Linux Repository" that corresponds to your operating system. For example, an archived repository may look like this (version 2.5.103 on Ubuntu 18.04):
deb https://deb.openalpr.com/snapshot/bionic-2.5.103/ bionic main
Insert that repository into the following command and execute the commands:
curl -L https://deb.openalpr.com/openalpr.gpg.key | sudo apt-key add -
echo '[###PASTE THE REPOSITORY HERE###]' | sudo tee /etc/apt/sources.list.d/openalpr.listsudo apt-get update; sudo apt-get install -o apt::install-recommends=true -y openalpr openalpr-daemon openalpr-linksudo rm /etc/apt/sources.list.d/openalpr.list