Error: Cannot modify header information

Hey, I’m having a problem after moving my site to another host I can not see my site and instead get this message: Warning: Cannot modify header information – headers already sent by (output started at /home/howtoeas/public_html/wp-content/themes/wp-altera/functions.php:1) in /home/howtoeas/public_html/wp-includes/pluggable.php on line 1178

I didn’t change the files at all so I’m confused. Any idea what to do?

The only things that have changed are the host and the domain but I changed the database accordingly.

tnx