Looks like a problem similar to these posts:

http://forums.b2evolution.net/viewtopic.php?p=12575
http://forums.b2evolution.net/viewtopic.php?p=14110

They were caused by extra whitespace at the end of files. The files in the /conf/ folder might be the ones. So open up any files you've edited and make sure there's no whitespace after the last ?>

I also get this error.

I just upgraded to 0.9.1. and everything else seems to be working fine.

I haven't edited any files yet, so I don't believe trailing blanks after ?> are the problem. I double checked to be sure.

I can't test this any more, but I believe I got errors with static file generation in 0.9.0.12 as well. Something to do with file permissions?

If possible, I would really like to get this to work. My SQL server is having a hard time, as I explained in another thread.
http://forums.b2evolution.net/viewtopic.php?t=5746

Thanks for your help

Onegen

Make sure the static file exists and is writable by the web server (make it world writable if you're not sure). I wouldn't expect a permissions problem to give that particular error, but we should check that to make sure.

Creating the file didn't help. I am supposed to make it in the root folder of my blog, right?

Anyway, I've been trying to find out what is going on.
Somewhere in the process of generating a static file, this file is called:
/www/html/icriblog/b2evocore/_404_not_found.page.php

In the header it says:
This page displays an error message when we cannot resolve the extra path.

*

* This happens when you request an url of the form http://.../some_stub_file.php/some_malformed_extra_path/...

I've been looking at the file admin/b2blogs.php to see what could lead to a 404 not found:

On line 527 this file is requested:
require $basepath.'/'.$core_subdir.'/_blog_main.php';

This file exists but if you access it directly it tells you no blog has been selected.
When I put in an echo statement on the next line - in an attempt to find out where the script stops working - it doesn't get printed.

I don't have time to investigate this further right now, maybe later. Possible, there is a bug here somewhere.

Onegen

Creating the file didn't help. I am supposed to make it in the root folder of my blog, right?

If you're getting a 404 error, then this probably is the problem. The static file needs to be in the same folder as your stub file or index.php file. And make sure it's writable. If you give a link to your site, I'll be more able to tell you whether it's in the right place.

I am having the exact same problem, and it's not spaces after any files, because the installation is brand new and totally unmodified. Also, I didn't have this problem before, it appeared after I upgraded to Dawn.

I installed b2evo on the root of my domain. Here is what I get when I try to generate a static page:

Generating static page for blog...
Warning: Cannot modify header information - headers already sent by (output started at /home/*/public_html/admin/_menutop.php:14) in /home/*/public_html/b2evocore/_404_not_found.page.php on line 14
404 Not Found
b2evolution cannot resolve the requested URL.

Also tried creating the files manually, giving them 777 permission, etc, nothing worked.

Does anyone else have an idea of what should be tweaked for this static file generation to work? I am also having big server overload problems, and the static file is strictly necessary.

I'm not using stub files. But I did create the html file in the same folder as index.php

The site is currently password protected with a htaccess file. Otherwise the webserver admin was going to pull the plug completely.

I haven't looked any further at this file yet:

$basepath.'/'.$core_subdir.'/_blog_main.php

Maybe a variable isn't getting passed along properly? It's a wild guess.

I finally had some time dig into the file b2evocore/_blog_main.php

As far as I can tell, the problem is with the $ReqPath variable.

Normally, the requesting path calling _blog_main.php is something like /BLOGNAME/index.php?blog=2&cat=1

When trying to generate a static file from the backend, the variable $ReqPath is /BLOGNAME/admin/b2blogs.php

I haven't been able to find out where the variable $ReqPath is defined. It appears to me that it must come from another file.

Another thing, in the url a variable is included "action=GenStatic", but I haven't found a place where it is used yet. This could be used to bypass the $ReqPath of course.

Does this make sense to anyone?

Ok, the search is over:

A solution is described here:
http://forums.b2evolution.net/viewtopic.php?p=28179