Error with uploading Asset Files: net::ERR_EMPTY_RESPONSE In my local MAMP site I'm not able to upload any files. 

Gives me this error in Chrome: 

http://nobel.craft.dev:8888/index.php?p=admin/actions/assets/uploadFile net::ERR_EMPTY_RESPONSE 

This error in Safari

"Failed to load a resource: The network connection was lost."

Things I did


I've checked the asset folder path
makes sure folder is writable
nothing strange in the craft.log
delete cache in admin
download new version of craft and replaced the app folder
That usually means "something fatal happened" when trying to upload the file.  The usual culprits are the php.ini max_execution_time and memory_limit settings, but if it's happening for small files too, something else could be going on.

Have also seen it happen when you're uploading an image in a format your underlying image processing library doesn't support.  i.e. your server has GD installed, but you're trying to upload a 32-bit PNG.  Or you're running an older version of GD or Imagick that has a bug you're hitting.

Check if you have a craft/storage/runtime/logs/phperrors.log file.  Any PHP fatal errors will be logged there.  If not, then check the Apache error logs to see if it's an Apache problem.