Hi
I change my theme to 7dana and my site become blank page.
I change the theme back and deleted all files under templates_c, but my site still blank.

How can I fix this? and what caused the problem?

What happens if, as well as changing the theme, you enable the "Check for new templates" option?

what 7 dana theme?

stupid question, but...
In the 7dana folder is there a hole lot of files and 1 or more folders? if you just see a text file and 1 folder, then your not in the correct place.

one thing you can do ( and this is if you have the " Preferences Main »» General Settings >> Update module template .html files from themes/your theme/templates directory? " set to yes ...
change any " working " theme name you have to the bad theme ( 7dana )
and clear the templates_c file

or

2nd you can edit the SQL file so your in default and not the 7dana

Marc