anthb

What exactly is your problem? Please describe in detail.

Resolving this “cannot modify header” issue also has another effect on wp2.2.1: it makes the post-new.php (write>write post) work correctly.

Normally you would notice the “cannot modify header” error messages during login or logout (or just after activating a plugin maybe?), but another way to know that this is happening is when you would just get a blank page after writing a post and hitting publish.

When you then fix the error the post-new.php works correctly and you just get the writing interface back instead of a blank page.

Just had the same error (on wp 2.2.1):

Warning: Cannot modify header information – headers already sent by (output started at /home/ininon/public_html/my-beauty-info/wp-content/plugins/beta12b-linking-plugin-v4.php:1) in /home/userb2/public_html/my-beauty-info/wp-login.php on line 12 (mbic)

Removing the empty line behind the ?>tag did not fix it.

Here’s what I did:

1. Take the plugin that was causing an issue and open it in notepad
2. Copy the entire contents (CTRL-A)
3. Create a new .txt file and paste the entire contents (CTRL-V)
4. Save and compare the file size with right-click file > properties

Results: one file (the old one) was 72,800 bytes, while the new one was 72,796 – 4 bytes less.

Maybe the programming software that the coder was using wrote a special char to the end of the file that conflicted with WordPress.

It may also be that the wordpress charset settings conflict with the coder’s programming software or something like that.

This fixed the issue, and I think you could fix most plugins like this!