I think the error from $_SERVER[‘REQUEST_URI’].
If you rule like,
RewriteRule /html/(.+)\.html /index.php?p=$1
then request https://target/html/123.html,infact https://target/index.php?p=123 requeted.
in apache $_SERVER[‘REQUEST_URI’]=’/html/123.html’
but in IIS $_SERVER[‘REQUEST_URI’]=’/index.php?p=123′
so…..
(sorry,bad english~)