Potential change to wp-config.php
I have also run into situations where I have had to add this to the wp-config.php –
WordPress Multisite – Network Admin Settings
You must also pay attention to this within a WordPress Multisite
Upper left hand corner – My Sites -> Network Admin -> Settings –
Down towards the bottom, you will see a line that says:
Max Upload File Size – set that to 65536 kb (64mb)
***I came across a set of sites tonight where this was set to 1500 kb (1 mb) – Not sure if someone had changed it or if that is some sort of default.