
Hi,
We're running the latest version of Observium. Today we get "PHP Fatal error: html_callback_build_title(): Cannot use output buffering in output buffering display handlers in /opt/observium/html/includes/functions.inc.php on line 130"
Returns a blank page (after ok login)
-- Best regards, Henrik.
________________________________
Region Hovedstaden anvender de personoplysninger, du giver os i forbindelse med din henvendelse. Du kan læse mere om formålet med anvendelsen samt dine rettigheder på vores hjemmeside: www.regionh.dk/persondatapolitik

Hi,
you need to show versions (or screenshot of about page, or from cli)
./discovery.php -VV
It seems you use the not latest version, because the function indicated in the error is in another line. I can't reproduce or see such error.
Henrik Aarfeldt via observium wrote on 21.03.2025 11:40:
Hi,
We're running the latest version of Observium. Today we get "PHP Fatal error: html_callback_build_title(): Cannot use output buffering in output buffering display handlers in /opt/observium/html/includes/functions.inc.php on line 130"
Returns a blank page (after ok login)
-- Best regards, Henrik.
Region Hovedstaden anvender de personoplysninger, du giver os i forbindelse med din henvendelse. Du kan læse mere om formålet med anvendelsen samt dine rettigheder på vores hjemmeside: www.regionh.dk/persondatapolitik _______________________________________________ observium mailing list -- observium@lists.observium.org To unsubscribe send an email to observium-leave@lists.observium.org

Morning,
##### Observium #####
o Version 25.3.13962 o Train rolling o Released 20th March 2025 o Subscription User aarfeldt-3723
##### Software versions #####
o OS Linux 5.15.0-134-generic [amd64] (Ubuntu 22.04) o Apache 2.4.52 o PHP 8.1.2-1ubuntu2.20 (OPcache: DISABLED) o Python 3.10.12 o MySQL 8.0.41-0ubuntu0.22.04.1 (extension: mysqli 8.1.2-1ubuntu2.20) o SNMP NET-SNMP 5.9.1 o RRDtool 1.7.2 o Fping 5.1 (IPv4 and IPv6) o Fetch PHP fetch
##### PHP info #####
o Memory Limit Unlimited o Math NATIVE
##### DB info #####
o DB schema 497 o MySQL binlog OFF o MySQL mode NO_ENGINE_SUBSTITUTION
##### Charset info #####
o PHP UTF-8 o MySQL utf8mb3
##### Timezones info #####
o Date Monday, 24-Mar-25 06:31:16 CET o PHP +01:00 o MySQL +01:00
-- Med venlig hilsen
Henrik Aarfeldt IT-specialist Drift > Driftsstyring > Overvågning Overvågning + SårbarhedsKortlægning + NetværksKvalitetsMålinger + Elastic. Mobil: +45 2494 8281 Mail: Henrik.Aarfeldt@RegionH.dk
Region Hovedstaden Center for IT og MedicoTeknologi, CIMT Borgervænget 5 2100 København Ø
Ferie uge 17.
Fra: Mike Stupalov via observium observium@lists.observium.org Sendt: 22. marts 2025 14:07 Til: Observium observium@lists.observium.org; Henrik Aarfeldt via observium observium@lists.observium.org Cc: Henrik Aarfeldt Henrik.Aarfeldt@regionh.dk; Mike Stupalov mike@observium.org Emne: [Observium] Re: PHP Fatal error
Hi,
you need to show versions (or screenshot of about page, or from cli)
./discovery.php -VV
It seems you use the not latest version, because the function indicated in the error is in another line. I can't reproduce or see such error.
Henrik Aarfeldt via observium wrote on 21.03.2025 11:40:
Hi,
We're running the latest version of Observium.
Today we get "PHP Fatal error: html_callback_build_title(): Cannot use output buffering in output buffering display handlers in /opt/observium/html/includes/functions.inc.php on line 130"
Returns a blank page (after ok login)
--
Best regards, Henrik.
________________________________
Region Hovedstaden anvender de personoplysninger, du giver os i forbindelse med din henvendelse. Du kan læse mere om formålet med anvendelsen samt dine rettigheder på vores hjemmeside: www.regionh.dk/persondatapolitikhttp://www.regionh.dk/persondatapolitik
_______________________________________________
observium mailing list -- observium@lists.observium.orgmailto:observium@lists.observium.org
To unsubscribe send an email to observium-leave@lists.observium.orgmailto:observium-leave@lists.observium.org
-- Mike Stupalov, Discord channel: https://discord.gg/GjpNXKWm8W Observium Limited, https://observium.org
________________________________
Region Hovedstaden anvender de personoplysninger, du giver os i forbindelse med din henvendelse. Du kan læse mere om formålet med anvendelsen samt dine rettigheder på vores hjemmeside: www.regionh.dk/persondatapolitik

What changed between the last time you didn't get this error, and the first time you did get this error?
There are two likely causes for this error:
1) ob_start() is being called inside an existing ob_start(), this is pretty unlikely because it'd break everything for everyone
2) the output buffering is running out of memory mid-buffer, if this is the case the error you showed will be followed by another one complaining about exhausted memory
It's also possible that you have some local changes that have somehow managed to mean ob_start() is caused twice, but that's pretty unlikely. You can find any possible local changes with "svn status"
Thanks, adam.
Henrik Aarfeldt via observium wrote on 24/03/2025 05:32:
Morning,
##### Observium #####
o Version 25.3.13962
o Train rolling
o Released 20th March 2025
o Subscription User aarfeldt-3723
##### Software versions #####
o OS Linux 5.15.0-134-generic [amd64] (Ubuntu 22.04)
o Apache 2.4.52
o PHP 8.1.2-1ubuntu2.20 (OPcache: DISABLED)
o Python 3.10.12
o MySQL 8.0.41-0ubuntu0.22.04.1 (extension: mysqli 8.1.2-1ubuntu2.20)
o SNMP NET-SNMP 5.9.1
o RRDtool 1.7.2
o Fping 5.1 (IPv4 and IPv6)
o Fetch PHP fetch
##### PHP info #####
o Memory Limit Unlimited
o Math NATIVE
##### DB info #####
o DB schema 497
o MySQL binlog OFF
o MySQL mode NO_ENGINE_SUBSTITUTION
##### Charset info #####
o PHP UTF-8
o MySQL utf8mb3
##### Timezones info #####
o Date Monday, 24-Mar-25 06:31:16 CET
o PHP +01:00
o MySQL +01:00
--
Med venlig hilsen
Henrik Aarfeldt
IT-specialist
Drift > Driftsstyring > Overvågning
Overvågning + SårbarhedsKortlægning + NetværksKvalitetsMålinger + Elastic.
Mobil: +45 2494 8281
Mail: Henrik.Aarfeldt@RegionH.dk
Region Hovedstaden Center for IT og MedicoTeknologi, CIMT
Borgervænget 5
2100 København Ø
Ferie uge 17.
*Fra:*Mike Stupalov via observium observium@lists.observium.org *Sendt:* 22. marts 2025 14:07 *Til:* Observium observium@lists.observium.org; Henrik Aarfeldt via observium observium@lists.observium.org *Cc:* Henrik Aarfeldt Henrik.Aarfeldt@regionh.dk; Mike Stupalov mike@observium.org *Emne:* [Observium] Re: PHP Fatal error
Hi,
you need to show versions (or screenshot of about page, or from cli)
./discovery.php -VV
It seems you use the not latest version, because the function indicated in the error is in another line. I can't reproduce or see such error.
Henrik Aarfeldt via observium wrote on 21.03.2025 11:40:
Hi, We're running the latest version of Observium. Today we get "PHP Fatal error: html_callback_build_title(): Cannot use output buffering in output buffering display handlers in /opt/observium/html/includes/functions.inc.php on line 130" Returns a blank page (after ok login) -- Best regards, Henrik. ________________________________ Region Hovedstaden anvender de personoplysninger, du giver os i forbindelse med din henvendelse. Du kan læse mere om formålet med anvendelsen samt dine rettigheder på vores hjemmeside:www.regionh.dk/persondatapolitik <http://www.regionh.dk/persondatapolitik> _______________________________________________ observium mailing list --observium@lists.observium.org <mailto:observium@lists.observium.org> To unsubscribe send an email toobservium-leave@lists.observium.org <mailto:observium-leave@lists.observium.org>
-- Mike Stupalov, Discord channel: https://discord.gg/GjpNXKWm8W Observium Limited, https://observium.org
Region Hovedstaden anvender de personoplysninger, du giver os i forbindelse med din henvendelse. Du kan læse mere om formålet med anvendelsen samt dine rettigheder på vores hjemmeside: www.regionh.dk/persondatapolitik
observium mailing list -- observium@lists.observium.org To unsubscribe send an email to observium-leave@lists.observium.org

Hi,
Seems like it’s solved now. Increased “Minimum PHP memory limit” to 512M.
Thanks to Landy/Mike for the help.
Regards, Henrik.
Fra: Adam Armstrong via observium observium@lists.observium.org Sendt: 24. marts 2025 13:35 Til: Henrik Aarfeldt via observium observium@lists.observium.org Cc: Adam Armstrong adama@observium.org Emne: [Observium] Re: PHP Fatal error
What changed between the last time you didn't get this error, and the first time you did get this error?
There are two likely causes for this error:
1) ob_start() is being called inside an existing ob_start(), this is pretty unlikely because it'd break everything for everyone
2) the output buffering is running out of memory mid-buffer, if this is the case the error you showed will be followed by another one complaining about exhausted memory
It's also possible that you have some local changes that have somehow managed to mean ob_start() is caused twice, but that's pretty unlikely. You can find any possible local changes with "svn status"
Thanks, adam.
Henrik Aarfeldt via observium wrote on 24/03/2025 05:32:
Morning,
##### Observium #####
o Version 25.3.13962 o Train rolling o Released 20th March 2025 o Subscription User aarfeldt-3723
##### Software versions #####
o OS Linux 5.15.0-134-generic [amd64] (Ubuntu 22.04) o Apache 2.4.52 o PHP 8.1.2-1ubuntu2.20 (OPcache: DISABLED) o Python 3.10.12 o MySQL 8.0.41-0ubuntu0.22.04.1 (extension: mysqli 8.1.2-1ubuntu2.20) o SNMP NET-SNMP 5.9.1 o RRDtool 1.7.2 o Fping 5.1 (IPv4 and IPv6) o Fetch PHP fetch
##### PHP info #####
o Memory Limit Unlimited o Math NATIVE
##### DB info #####
o DB schema 497 o MySQL binlog OFF o MySQL mode NO_ENGINE_SUBSTITUTION
##### Charset info #####
o PHP UTF-8 o MySQL utf8mb3
##### Timezones info #####
o Date Monday, 24-Mar-25 06:31:16 CET o PHP +01:00 o MySQL +01:00
-- Med venlig hilsen
Henrik Aarfeldt IT-specialist Drift > Driftsstyring > Overvågning Overvågning + SårbarhedsKortlægning + NetværksKvalitetsMålinger + Elastic. Mobil: +45 2494 8281 Mail: Henrik.Aarfeldt@RegionH.dkmailto:Henrik.Aarfeldt@RegionH.dk
Region Hovedstaden Center for IT og MedicoTeknologi, CIMT Borgervænget 5 2100 København Ø
Ferie uge 17.
Fra: Mike Stupalov via observium observium@lists.observium.orgmailto:observium@lists.observium.org Sendt: 22. marts 2025 14:07 Til: Observium observium@lists.observium.orgmailto:observium@lists.observium.org; Henrik Aarfeldt via observium observium@lists.observium.orgmailto:observium@lists.observium.org Cc: Henrik Aarfeldt Henrik.Aarfeldt@regionh.dkmailto:Henrik.Aarfeldt@regionh.dk; Mike Stupalov mike@observium.orgmailto:mike@observium.org Emne: [Observium] Re: PHP Fatal error
Hi,
you need to show versions (or screenshot of about page, or from cli)
./discovery.php -VV
It seems you use the not latest version, because the function indicated in the error is in another line. I can't reproduce or see such error.
Henrik Aarfeldt via observium wrote on 21.03.2025 11:40:
Hi,
We're running the latest version of Observium.
Today we get "PHP Fatal error: html_callback_build_title(): Cannot use output buffering in output buffering display handlers in /opt/observium/html/includes/functions.inc.php on line 130"
Returns a blank page (after ok login)
--
Best regards, Henrik.
________________________________
Region Hovedstaden anvender de personoplysninger, du giver os i forbindelse med din henvendelse. Du kan læse mere om formålet med anvendelsen samt dine rettigheder på vores hjemmeside: www.regionh.dk/persondatapolitikhttp://www.regionh.dk/persondatapolitik
_______________________________________________
observium mailing list -- observium@lists.observium.orgmailto:observium@lists.observium.org
To unsubscribe send an email to observium-leave@lists.observium.orgmailto:observium-leave@lists.observium.org
-- Mike Stupalov, Discord channel: https://discord.gg/GjpNXKWm8W Observium Limited, https://observium.org
________________________________
Region Hovedstaden anvender de personoplysninger, du giver os i forbindelse med din henvendelse. Du kan læse mere om formålet med anvendelsen samt dine rettigheder på vores hjemmeside: www.regionh.dk/persondatapolitikhttp://www.regionh.dk/persondatapolitik
_______________________________________________
observium mailing list -- observium@lists.observium.orgmailto:observium@lists.observium.org
To unsubscribe send an email to observium-leave@lists.observium.orgmailto:observium-leave@lists.observium.org
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________________________________
Region Hovedstaden anvender de personoplysninger, du giver os i forbindelse med din henvendelse. Du kan læse mere om formålet med anvendelsen samt dine rettigheder på vores hjemmeside: www.regionh.dk/persondatapolitik
participants (3)
-
Adam Armstrong
-
Henrik Aarfeldt
-
Mike Stupalov