Hi Joshua,
On 11 Jan 2016 at 21:35:31, Joshua Spiva (jspiva@emdinc.com(mailto:jspiva@emdinc.com))
wrote:
  I can't get my attachment limit above 4Mb. I am
running 7.4 on Tomcat 8 with MySQL5.6 all running on Server 2012 R2.
 I have included screenshots of the current settings in Xwiki and MySQL
 Xwiki Maximum Upload Size = 3000000000
 MySQL max_allowed_packet = 900M
 Any help would be greatly appreciated.   
Sorry I don’t have the time to reproduce right now (maybe someone can?) but what I know is
that switching to Filesystem attachments should solve all the attachment size issues you
may have (I have tested that with 1GB attachments and it was working fine).
See 
http://platform.xwiki.org/xwiki/bin/view/AdminGuide/Attachments#HAttachment…
That said, it would be nice to get to the bottom of your issue to understand the real
problem since 4MB isn’t that large and should work fine (we mention 30MB as the limit for
DB-stored attachments in the doc).
Thanks
-Vincent
  Joshua Spiva I.T. Manager
 1411 Twin Oaks Street, Wichita Falls, TX 76302
 tel: (940) 322-2206
 dir: (940) 264-9114
 jspiva(a)emdinc.com