Cannot Modify Header Information; Another One

First off, I’d like to apologize because it seems like people have this issue all the time. However, after going through their threads, I wasn’t able to solve my issue. I also read the support thread by WordPress with no help.

I have the following errors at the top of my wordpress dashboard:
Warning: Cannot modify header information – headers already sent by (output started at /home/content/24/10650724/html/wp-content/themes/Retro/haku/functions.php:1) in /home/content/24/10650724/html/wp-includes/option.php on line 568

Warning: Cannot modify header information – headers already sent by (output started at /home/content/24/10650724/html/wp-content/themes/Retro/haku/functions.php:1) in /home/content/24/10650724/html/wp-includes/option.php on line 569

I know from some reading that this means that the error is in Functions.php on line one. Generally people have fixed this by opening it in Notepad (I have a Mac so my next best bet is “textedit”) and they simply delete the space that is at the beginning of the end of the file. Sadly…I dont have a space to delete and reupload from FTP.

After I go in and “Update the File” from the editor window in wordpress I also get this error:

Warning: Cannot modify header information – headers already sent by (output started at /home/content/24/10650724/html/wp-content/themes/Retro/haku/functions.php:1) in /home/content/24/10650724/html/wp-includes/pluggable.php on line 876

A lot of people said that because “Pluggable” was listed, that means it was a plugin issue. I have deleted all of the plugins with no success.

Any additional information you can give me would be AMAZING.