I cannot access local HTML files at external SD card on my Lenovo S6000 within Chrome. It is mounted at /mnt/extSdCard. Browsing to file:///mnt/extSdCard does show this message:
The file at file:///storage/sdcard0/foo/bar.html is not readable. It may have been removed, moved, or file permissions may be preventing access. Error code (ERR_ACCESS_DENIED)
I've tried multiple browsers. Some show the app and doesn't work, some show the app and does work, some show the above error. Interestingly, I have 2 tablets. The one with updated firmware is the one that doesn't work. I held off on the update on the 2nd and Chrome works with local HTML files.
$ls -l index.html
-rw-rw-r-- root sdcard_rw 8097 2013-11-20 10:40 index.html