Purging a category caused the following error. Categories list no lonnger loads.
Now the log shows this error.
NodeBB - v1.0.3
Ubuntu 14.04.04 LTS
Nginix
5/5 13:50 [2606] - error: TypeError: Cannot read property 'children' of undefined
at Object.helpers.generateChildrenCategories (/var/www/nodebb/public/src/modules/helpers.js:107:11)
at callMethod (/var/www/nodebb/node_modules/templates.js/lib/templates.js:279:17)
at parseFunctions (/var/www/nodebb/node_modules/templates.js/lib/templates.js:303:55)
at parseArrayBlock (/var/www/nodebb/node_modules/templates.js/lib/templates.js:380:14)
at parseArray (/var/www/nodebb/node_modules/templates.js/lib/templates.js:346:13)
at parse (/var/www/nodebb/node_modules/templates.js/lib/templates.js:416:16)
at parseTemplate (/var/www/nodebb/node_modules/templates.js/lib/templates.js:133:14)
at Object.templates.parse (/var/www/nodebb/node_modules/templates.js/lib/templates.js:119:11)
at /var/www/nodebb/node_modules/templates.js/lib/templates.js:169:30
at FSReqWrap.readFileAfterClose [as oncomplete] (fs.js:380:3)
TypeError: Cannot read property 'children' of undefined
at Object.helpers.generateChildrenCategories (/var/www/nodebb/public/src/modules/helpers.js:107:11)
at callMethod (/var/www/nodebb/node_modules/templates.js/lib/templates.js:279:17)
at parseFunctions (/var/www/nodebb/node_modules/templates.js/lib/templates.js:303:55)
at parseArrayBlock (/var/www/nodebb/node_modules/templates.js/lib/templates.js:380:14)
at parseArray (/var/www/nodebb/node_modules/templates.js/lib/templates.js:346:13)
at parse (/var/www/nodebb/node_modules/templates.js/lib/templates.js:416:16)
at parseTemplate (/var/www/nodebb/node_modules/templates.js/lib/templates.js:133:14)
at Object.templates.parse (/var/www/nodebb/node_modules/templates.js/lib/templates.js:119:11)
at /var/www/nodebb/node_modules/templates.js/lib/templates.js:169:30
at FSReqWrap.readFileAfterClose [as oncomplete] (fs.js:380:3)
5/5 13:50 [2606] - info: [app] Shutdown (SIGTERM/SIGINT) Initialised.
5/5 13:50 [2606] - info: [app] Database connection closed.
5/5 13:50 [2606] - info: [app] Web server closed to connections.
5/5 13:50 [2606] - info: [app] Shutdown complete.
[cluster] Child Process (2606) has exited (code: 1, signal: null)
[cluster] Spinning up another process...
Should be fixed in master and 1.x.x can you update and try again.
Were there any errors when you purged the category?
Thanks! The upgrade from master fixed the issue.
Sorry could not capture the error logs. But the issue was caused upon adding a new child category it showed duplicate child categories and upon deleting the duplicates it caused the issue. Hope this helps.
After the upgrade now we have 2 zombie categories. Anyway to remove that?
These are not shown in admin only in categories list.
thanks
Having the same issue as well! I am going to go ahead and upgrade to master, as well.
Do you have reproduction steps to cause duplicate categories? And does it happen on master?
Sorry. I don't have specific reproduction steps . No it does not happen after the master upgrade. Now i am facing another issue part from the zombie categories. If i create new category and inherit from existing category it does not show in front end and shows only in the admin categories list.
If your forum is public post a link to it so we can take a look.
It is not a public forum. 
Maybe try the solutions here https://community.nodebb.org/topic/3342/issue-with-categories-forums-won-t-display-the-homepage-anymore
I updated to master and made the most recent pulls.
I also have 2 empty ghost categories
@h0lybyte Which database are you using? You can remove the ghost categories from the correct sorted set to get rid of them.
KBVE: KiloByte Virtual Enterprise
