I recently work with Windows 8.1 and El capitan in 2 different computers. I use dropbox to sync my project files that is located in dropbox which the dropbox itself located in htdocs. I have no problem working with windows. the dropbox folder is accessible from browser. but it doesn't work in my Mac, I have tried to allow all access via http.conf but it seems something else should be configured to allow me to access dropbox via my browser. anyone have experienced and fixed this before?
I finally fixed this issue. The problem is simply in accessibility of the Dropbox folder that is placed inside the Htdocs folder. I just change the the folder accessibility by changing it from folder info on mac. It's not as complicated as what I expected before. So, if you have problem in syncing your htdocs folder using dropbox, just change the folder permission by go to right clicks, get info and change it from no access to read and write. problem solved.
P.S if you want to sync only the files of your project without sync the database (Mysql) just put your dropbox folder inside the htdocs and it's done. if you experience the error 403 do what I have done in the description above.