I tried to install the SemanticMediaWiki extension v0.6 (current) on 1.9.0 and got the same symptom as I reported with a vanilla installation of 1.8.2 in the thread Empty pages..., ie just HTML head and body tags with no content.
Rob Church advised in that thread to try setting $wgDisableCounters = true; so I tried that in this situation, despite the fact that what that was intended to work-around was supposedly fixed in 1.9.0. But I got a result: with that in place I got the error message:
Fatal error: Class 'SMW_LanguageEn' not found in C:\Domains\intersp.org\wwwroot\extensions\SemanticMediaWiki\includes\SMW_GlobalFunctions.php on line 136
I've gone over the semediawiki installation instructions several times and I'm sure I've done everything correctly. I haven't yet looked for any more appropriate forum to report this problem, but I thought that people here might be interested in what it took to get that error message. Here's the MW installation report again (for 1.8.2), let me know if any other info would help:
PHP 5.1.6 installed Found database drivers for: MySQL Warning: PHP's register_globals option is enabled. Disable it if you can. MediaWiki will work, but your server is more exposed to PHP-based security vulnerabilities. PHP server API is cgi-fcgi; using ugly URLs (index.php?title=Page_Title) Have XML / Latin1-UTF-8 conversion support. PHP is configured with no memory_limit. Have zlib support; enabling output compression. Couldn't find Turck MMCache, eAccelerator or APC. Object caching functions cannot be used. GNU diff3 not found. Found GD graphics library built-in, image thumbnailing will be enabled if you enable uploads. Installation directory: C:\Domains**** Script URI path: Environment checked. You can install MediaWiki. Warning: $wgSecretKey key is insecure, generated with mt_rand(). Consider changing it manually. Generating configuration file...
Database type: MySQL Loading class: DatabaseMysql Attempting to connect to database server as ****...success. Connected to 4.1.21-community-max-nt-log Database **** exists Creating tables... using MySQL 4 table defs... done. Initializing data... Created sysop account ****. Initialising "MediaWiki" namespace for language code en... Done. Updated: 0, inserted: 1495, kept: 0. Creating LocalSettings.php...
Installation successful! Move the config/LocalSettings.php file into the parent directory, then follow this link to your wiki.