This page explains various common problems when running Semantic MediaWiki and how to fix them. Problems that are not in this list may be solved by SMW's support facilities or may be software bugs that you may wish to report.
 Database errors: unknown/nonexistent table
- Previewing or storing articles with semantic properties causes database errors.
Most likely, your database was not initialized properly. Go to the page Special:SMWAdmin on your wiki for instructions. If all fails, run the maintenance script "SMW_refreshData -vfp" (followed by "SMW_refreshData -v" if you already stored annotations).
 Wrong or incomplete data
- Data has been entered and shows up in the Factbox, but it is not shown when using Special:Browse.
- Semantic queries do not return the expected results.
It is possible that the data used by SMW is not in synch with the page contents in your wiki. To check this, edit a page that is affected and use Special:Browse to see if its data is now correct. To fix all pages automatically, read Help:Repairing SMW's data. If this was not your problem look at the next item.
 Missing data on custom namespaces
- Data entered on pages in my custom namespace (e.g. "Portal:") is ignored, and queries do not show any pages of my custom namespace.
Make sure your custom namespace is listed in $smwgNamespacesWithSemanticLinks. Read SMW_Settings.php for details. If this fails, check whether you have restricted queries to certain namespaces using $smwgNamespacesWithSemanticLinks.
 Database errors: illegal collation
- When issuing semantic queries, I receive database errors that talk about some "illegal collation". Otherwise storing of annotations seems to work.
Your database tables for MediaWiki and SMW have been generated with different settings. To fix the problem, first try to run the maintenance script "SMW_refreshData -vfp" followed by "SMW_refreshData -v". If this does not help, you need to investigate the collation/character set settings of your DB. To do that, use a DB frontend tool or the SQL command "SHOW CREATE TABLE tablename;". Look up the collation/charset of, e.g., the table "categorylinks" and change the default collation/charset of your DB to these settings as described in the MySQL manual. Finally, run the aforementioned maintenance scripts again.
 Non-English language fails
- In my non-English installation, properties don't work even when I follow the examples.
Although SMW normally provides English aliases, you may need to use the localised names for special properties and namespaces. The translated strings and aliases for each language are in the languages subdirectory.
 Blank or incomplete pages
- After installing SMW, some or all pages are not displayed at all, or just incompletely.
This is usually due to the restrictive memory default settings on some sites, and is not directly caused by SMW (any additional extension code might cause this). Uncomment the line
ini_set( 'memory_limit', '20M' );
in LocalSettings.php and possibly adjust the value to your needs. More than 100M is harldy useful, but values around 50M might be required for large pages in some cases.
Help:Troubleshooting en 1.0