900 "not found" errors in first 36 hours....yikes!

I've just updated about 36 hours ago, and have already logged nearly 900 errors in the error log.  This is pretty bad, right?  What might I have done wrong in my configuration to have created this cavalcade of errors?  ???

Thanks in advance for your help.

First read what the log says and accessing the URLs, together with debug, try to locate the error.
The most common error in configurations is with URL replace: www.sakic.net/support/faq/sef_advance/#19

i'm getting the same problem here, i checked my logs, the component is rewriting the urls but when i click the link is going to 404, only making aliases is working

You should also check the FAQ, this one in particular: www.sakic.net/support/faq/sef_advance/#19

Emir, thanks, firts i checked i didn have so many replacements, second chance you said i checked and it aws a "," i deleted and now is working,thank you for your help
;D

Hi Emir

It would probably help if the 404 errors were sorted by occurence.

Currently its hard to wade through 100s of URLs without knowing which ones are urgent.