[pmwiki-devel] Cannot Save Larger Pages

[Petko Yotov]

Great, I'll add this to Troubleshooting.

Petko

On 11/06/2026 15:50, Michael Elliott wrote:
> Its fixed!
> 
> Ending up being a Hosting company issue.  Below is that they said they
> changed to fix in case anyone else comes across this:
> 
>> During testing, we were able to reproduce behavior consistent with
>> the PHP warnings you previously reported.
>> The issue we found was that PHP was unable to create temporary files
>> in the configured temporary directory (D:\PHP\temp). This was
>> consistent with the warnings regarding temporary file creation and
>> POST data buffering.
>> 
>> To address this, we updated the permissions on the PHP temporary
>> directory and confirmed that PHP can now successfully create
>> temporary files.
>> After making this change, we performed additional testing using a
>> standalone PHP form and successfully processed POST requests larger
>> than 20 KB. This exceeds the approximately 14 KB threshold where you
>> reported the PMWiki save failures occurring.
>> 
>> Based on our testing, the issue does not appear to be related to the
>> configured PHP POST size limit or IIS request size limits.
> 
>  On Thursday, June 11, 2026 at 09:18:37 AM EDT, Michael Elliott
> <melliott42 at yahoo.com> wrote:
> 
> Petko, Team,
> 
> Thank you for the quick response.  I am working through all the
> options you presented.
> 
> Also, the troubleshooting page is really good.  I just never needed it
> before using PMwiki for many years. Shows how solid its been.
> 
> The Troubleshooting item below seemed to have my name on it but in
> initially creating a new page the issue still exists:
> 
>> Very long pages with thousands of lines may appear blank after
>> adding a few additional lines. This may be preformatted text, table,
>> or text inside conditional markup, or text in a custom markup
>> directive.
>> @ini_set('pcre.backtrack_limit', 10000000);
>> 
>> Testing this further...
> 
> I'll add that on some saves of pages with more data I sometimes get
> this (below) which would suggest it is in the PHP config:
> 
>> PHP Notice: Unknown: file created in the system's temporary
>> directory in Unknown on line 0
>> 
>> PHP Warning:  Unknown: Unable to create temporary file, Check
>> permissions in temporary files directory. in Unknown on line 0
>> PHP Warning:  Unknown: POST data can't be buffered; all data
>> discarded in Unknown on line 0
> 
> Thank you,
> 
> Michael
> 
>  On Thursday, June 11, 2026 at 07:18:54 AM EDT, Petko Yotov
> <5ko at 5ko.fr> wrote:
> 
> If this is a bug with the PmWiki core we'll fix it ASAP.
> 
> I just saved a 350kb page on pmwiki.org and the same one on my laptop
> 
> wiki, both running the pre-release after version 2.6.0.
> 
> What messages appear on the wiki or in the server's PHP error logs? A
> 
> 500 error almost certainly contains some indication in the error logs.
> 
> Do you see a blank 500 Internal Server Error page, or does the edit
> form
> 
> reappear unsaved, or does it redirect to the page that was not
> modified?
> 
> If you press Preview, does the preview page work?
> 
> Can you upload files larger than 14kb via the wiki?
> 
> Do you have mod_security enabled, or something similar that may block
> 
> the request for specific security-related keywords in the posted text?
> 
> Do you have enough disk space?
> 
> Can you save smaller pages, subsequently?
> 
> Can you create new pages that are larger? Can you delete pages? Can
> you
> 
> delete larger pages?
> 
> Is the problem with the full disk file size
> 
> (pmwiki/wiki.d/Main.HomePage) or with the size of the wiki markup text
> 
> 
> in the edit form?
> 
> Do you use any custom page store class?
> 
> Does this happen in one wikigroup, or in all wikigroups?
> 
> Can you save a small page but not a large one in the same wikigroup?
> 
> Check directory/file permissions under wiki.d/.
> 
> Do you have recipes that are only enabled on ?action=edit or that
> modify
> 
> $EditFunctions?
> 
> Does this happen in an empty PmWiki installation? If so, the problem
> may
> 
> be with the server configuration, otherwise it is more likely with a
> 
> local PmWiki customization. See Troubleshooting on how to track what
> is
> 
> causing this.
> 
>   https://pmwiki.org/Troubleshooting
> 
> Petko
> 
> On 11/06/2026 12:40, Michael Elliott wrote:
> 
>> Hello,
> 
>> 
> 
>> I started having an issue where saving pages where the data size is
> 
>> larger than ~14.5 fail.  I have multiple PMwiki instances and it is
> 
>> happening on all of them.  Upgrading to the latest PMwiki version
> had
> 
>> no effect.  I also purge all page history and also tried recreating
> 
>> the page using a new name with no effect.
> 
>> 
> 
>> I have been working intensely with my hosting company and they say
> 
>> there should be no issue (below).
> 
>> 
> 
>> We checked the standard server-side request size limits. PHP is
> 
>> currently allowing POST requests up to 24 MB, and IIS request
> 
>> filtering is allowing up to approximately 28.6 MB. A 14 KB save is
> far
> 
>> below both of those limits, so this does not appear to be caused by
> 
>> the normal PHP POST size limit or IIS request-size limit.
> 
>> 
> 
>> We are continuing to review this from the IIS/FastCGI side and will
> 
>> check for any related server-side errors or rules that may be
> 
>> triggering the 500 error during the PMWiki save request.
> 
>> 
> 
>> What can you recommend?
> 
>> 
> 
>> Thank you,
> 
>> 
> 
>> Michael Elliott