This may be a permissions error in writing to php_error.log.

Here is a possible solution.

Find the file system location of your php_errors.log based on the setting in your php.ini configuration file. On Windows O/S, the php.ini file is usually located at c:\php\php.ini

The php_errors.log is usually located somewhere like c:\php\logs\php_errors.log

Right click the php_errors.log file and select “properties” from the drop down list.

Select the “Security” tab.

See if the “IUSR” Username account and/or the “IIS_IUSRS (SVRNAME\IUSRS)” Group has/have “Modify” and “Write” permissions, in addition to “Read & Execute” and “Read” permissions.

You may need add the IUSR and IIS_IUSRS accounts to the permissions list. To do so, click in sequence the “Edit” button and the “Add” button and the “Advanced” button and the “Find Now” button and, holding down the CTRL key on your keyboard, select both the “IUSR” account name and “IIS_IUSRS” group name (and then click OK after selecting both or each) and select the IUSR account and, under the “Allow” column, check the “Modify” permissions checkbox which will grant both “Modify” and “Write” permissions to the IUSR account, and likewise, select the IIS_ISRS group and under the “Allow” column check the “Modify” checkbox next to the IIS_IUSRS group which will add both Modify and Write permissions to the IIS_IUSRS group.

Conclude with Ok to accept your changes.

Now, try to access your DokuWiki from the web. Hopefully, the 500 error is gone and your DokuWiki is publishing.

Next, use a good text editor, like Notepad++ to open / edit your php_errors.log file and see which error or warning is now being written to the log file (previously having been blocked due to lack of write permissions.) If there is a compatibility problem with a plugin, then update the offending Plug-in using Extension Manager in the Admin area of your DokuWiki. See this article by Andreas Gohr: https://www.patreon.com/posts/declaration-be-20638123