This is part of my mini Ghost series, where I document the problems I ran into during the migration and how I solved them. You can find the other posts at the bottom.
While I was messing around with my ghost upgrade, I encountered a strange error and I couldn't seem to find a solution for it online.
Message: Cannot read property 'engine' of undefined
In case you are just looking for the solution, here it is: The theme is probably missing and ghost can’t load your theme. If you want to know how I got myself into this situation, you can stick around for a bit more.
This problem came about when I was moving my ghost blog from my production development environment to the development environment to develop my theme. In order to have my posts locally, I simply copied the database file from the server to my local machine. (I use SQLite, that’s why the database is a file). Since my local theme folder name was different from the one on the server, ghost crashed when trying to start. The strange thing is that ghost doctor runs fine. So I presume they never thought people would change or rename their theme folder.
Another method is to edit the database directly. In the ghost settings table, there is a field called
theme. Set that field to
casper, which is the default ghost theme and you should be able to start ghost again.
I hope this helps someone.
I have added the full output below in case anyone needs it for debugging purposes.
jiaxun@jjjx-personal % ghost start + sudo systemctl is-active ghost_chaijiaxun-com ✔ Ensuring user is not logged in as ghost user ✔ Checking if logged in user is directory owner ✔ Checking current folder permissions + sudo systemctl is-active ghost_chaijiaxun-com ✔ Validating config ✔ Checking folder permissions ✔ Checking file permissions ✔ Checking content folder ownership ✔ Checking memory availability + sudo systemctl start ghost_chaijiaxun-com + sudo systemctl stop ghost_chaijiaxun-com ✖ Starting Ghost A GhostError occurred. Message: Cannot read property 'engine' of undefined Suggestion: journalctl -u ghost_chaijiaxun-com -n 50 Debug Information: OS: Ubuntu, v16.04 Node Version: v8.15.0 Ghost-CLI Version: 1.9.9 Environment: production Command: 'ghost start' Additional log info available in: /home/jiaxun/.ghost/logs/ghost-cli-debug-2019-01-16T07_10_35_928Z.log Try running ghost doctor to check your system for known issues. You can always refer to https://docs.ghost.org/api/ghost-cli/ for troubleshooting.