Cannot modify header warning

(@johneckman)

Getting lots of PHP Warnings on this plugin – any idea what might be going on?

[Mon Jan 14 17:03:01 2013] [error] [client 67.151.141.50] PHP Warning:  Cannot modify header information - headers already sent in /wp-content/plugins/bwp-google-xml-sitemaps/includes/class-bwp-simple-gxs.php on line 1503
[Mon Jan 14 17:03:01 2013] [error] [client 67.151.141.50] PHP Warning:  Cannot modify header information - headers already sent in /wp-content/plugins/bwp-google-xml-sitemaps/includes/class-bwp-simple-gxs.php on line 1520
[Mon Jan 14 17:03:01 2013] [error] [client 67.151.141.50] PHP Warning:  Cannot modify header information - headers already sent in /wp-content/plugins/bwp-google-xml-sitemaps/includes/class-bwp-simple-gxs.php on line 1521
[Mon Jan 14 17:03:01 2013] [error] [client 67.151.141.50] PHP Warning:  Cannot modify header information - headers already sent in /wp-content/plugins/bwp-google-xml-sitemaps/includes/class-bwp-simple-gxs.php on line 1523
[Mon Jan 14 17:03:01 2013] [error] [client 67.151.141.50] PHP Warning:  Cannot modify header information - headers already sent in /wp-content/plugins/bwp-google-xml-sitemaps/includes/class-bwp-simple-gxs.php on line 1524
[Mon Jan 14 17:03:01 2013] [error] [client 67.151.141.50] PHP Warning:  Cannot modify header information - headers already sent in /wp-content/plugins/bwp-goog
le-xml-sitemaps/includes/class-bwp-simple-gxs.php on line 1525

The actual warnings have the full path of course.

Doesn’t seem (so far) to be impacting the actual output

http://ww.wp.xz.cn/extend/plugins/bwp-google-xml-sitemaps/

Viewing 7 replies - 1 through 7 (of 7 total)

Plugin Author Khang Minh
(@oddoneout)

13 years, 4 months ago

Hi there,

It’s very possible that there are other plugins that output things before the sitemaps get generated (a single space could cause this). How many plugins are you using?

Thread Starter johneckman
(@johneckman)

13 years, 4 months ago

Well, I’m seeing the error on 3-4 different blogs, each of which are using different plugins.

I’ll have to find some time to play with enabling and disabling plugins to find which one might be the culprit – thanks.

Is that function called whenever the sitemap is requested?

Plugin Author Khang Minh
(@oddoneout)

13 years, 4 months ago

Which function are you referring to?

Thread Starter johneckman
(@johneckman)

13 years, 4 months ago

All of the header warnings seem to occur inside the class-bwp-simple-gxs.php in the function send_header – quick look suggests this is called anytime a new sitemap is generated (request comes in and sitemap isn’t in cache or cached copy is old?)

Plugin Author Khang Minh
(@oddoneout)

13 years, 4 months ago

Actually that function is called every time a sitemap is served (not generated, because BWP GXS has a cache mechanism).

So, have you had the chance to find which plugin is causing the issue?

Thread Starter johneckman
(@johneckman)

13 years, 4 months ago

Nope. Disabled a number of plugins and it stopped showing the warning, so I thought I had at least narrowed the field – but then I re-enabled them all and I am still not seeing further warnings in the log.

So, I still need to determine under what circumstances it occurs – the warning is not thrown every time a sitemap gets served only some of the times, in a pattern I can’t yet discern.

Plugin Author Khang Minh
(@oddoneout)

13 years, 4 months ago

To correctly debug this you should enable BWP GXS’s debug mode (it will disable caching and allows you to actually see error messages).

Viewing 7 replies - 1 through 7 (of 7 total)

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