I have just installed bbPress plugin into my WordPress (with Weaver II theme - based on TwentyEleven theme).
When I go to the forums root http://klymene.net/forums/ , the layout seems acceptable. You will see 2 forums listed - English and Hindi. You will also see that there is an indication of some content under English.
If you click on English http://klymene.net/forums/forum/english/ no topics are listed.
On top of page, you will see error message
Warning: preg_match() [function.preg-match]: Compilation failed: nothing to repeat at offset 1 in .../wp-includes/class-wp.php on line 201
Warning: preg_match() [function.preg-match]: Compilation failed: nothing to repeat at offset 1 in .../wp-includes/class-wp.php on line 202
You can go directly to http://klymene.net/forums/topic/test/ to see the topic which should be under the English forum. But there are no post action buttons (Reply, etc).
Additionally, on top of page, see error message:
Warning: preg_match() [function.preg-match]: Compilation failed: nothing to repeat at offset 1 in ../wp-includes/class-wp.php on line 201
Warning: preg_match() [function.preg-match]: Compilation failed: nothing to repeat at offset 1 in ../wp-includes/class-wp.php on line 202
Please help!
P.S. In Settings > Permalinks, the setting is
/%postname%/