Moodle上传scorm错误

I want to upload scorm zip file on moodle. The zip file was just only 7MB but when I tried to upload the file. The loading status will reset to 1% after a while. Until it give an error of:

ERROR: Invalid JSON string

But when I checked my php.ini file. All is set higher than the uploaded file size.

Any help will be much appreciated. Thank you.

btw: I'm using IIS, PHP 5, moodle 3.1.5

The most common problem is site errors messing up output of json response. Did you turn off the error message output? In the Administration menu find Debugging section and set error selectbox to NONE. See if problem persists