Redmine

I've recently migrated from an old turnkey server to a new Ubuntu 15 server. I have submissions coming by email, and if I send an attachment, it gets written to the files folder and is attached to the issue ticket. But if I try to attach a file through the web page, I get a generic error. Also, If I try to delete an issue that I submitted by email, I get an error:

An error occurred on the page you were trying to access.
If you continue to experience problems please contact your Redmine administrator for assistance.

If you are the Redmine administrator, check your log files for details about the error.

When I submit an issue by email, they are attributed to the same user I'm logged in with, and I can delete other issue, just not ones that I've emailed in.

I also can't figure out how to get logging to work so that I can see what's going wrong. I've created /usr/share/redmine/log/production.log and uncommented config.log_level = :debug in /usr/share/redmine/config/additional_environment.rb. Is this right?

Edit: forgot to add my system specs:

Environment:
Redmine version 2.5.2.devel
Ruby version 2.1.5-p273 (2014-11-13) [x86_64-linux-gnu]
Rails version 4.1.10
Environment production
Database adapter Mysql2
SCM:
Git 2.5.0
Filesystem
Redmine plugins:
no plugin installed