Warning - cannot modify header information

[WiltshireAirlines]

I know this question has been asked before but it didn't solve my problem. So, basically, whenever I login or log out it says that it can't modify header information:

Warning: Cannot modify header information - headers already sent by (output started at /home/u800717564/public_html/core/modules/Mission/Mission.php:1) in /home/u800717564/public_html/core/modules/Login/Login.php on line 143 Warning: Cannot modify header information - headers already sent by (output started at /home/u800717564/public_html/core/modules/Mission/Mission.php:1) in /home/u800717564/public_html/core/modules/Login/Login.php on line 154

Now please note that Mission.php is a file that I created manually, and this morning I had problems with encoding with and without BOM - which is likely the problem. However, I've tried changing the encoding for all the files (login.php, mission.php and local.config.php) that are important for this error and nothing has worked. I had this problem last time, but last time it was whitespace - this time it's not whitespace, it's encoding. I use Notepad++ and I've tried changing the encoding multiple times, nothing works.

[freshJet]

What's your first line in Mission.php?

[WiltshireAirlines]

<?php

But again remember that I think there's something hiding there due to the encoding.

[WiltshireAirlines]

Fixed the problem simply by deleted mission.tpl, mysterious.

[freshJet]

I wouldn't have thought it was an encoding issue. Leaving spaces before the PHP tag at the top can cause issues. What is the second line?

My original quesiton should have been what is the first line after the PHP tag...

[WiltshireAirlines]

I forget. What's so mysterious is that I copied and pasted the code that's in Mission.php to every other PHP module file, but only Mission.php had a problem. That's what I'm confused about.

[freshJet]

So...do you not need the file anymore?

[WiltshireAirlines]

I can do without it for now, I'll add it back later (probably recode it entirely, there was barely and code in it anyway)