Cannot upload file: Unknown server error (404)


for some unknown reason, we cannot upload files larger than approximately 26 mb in size to our JIRA instance. Our max attachment size is 100 mb, and the server storage size is 300+ gb.

We can upload files <25 mb without any issues at all, but as soon as you break that 25-26 mb boundry it throws that error in the subject line.

I cannot peg the source.

We're running a stand alone.

Windows Server 2008 R2 6.1

App container; Apache Tomcat/7.0.29

JIRA version 6.0.0

Any help is appreciated.



3 answers

Hi Adam

After making the change in the attachment size as set in this documentation:

You need to restart your instance to make the changes replicate.


Ricardo Carracedo.

Hello Ricardo,

I just restarted the instance, it made no difference. :(

Thanks for trying.


Hey Adam,

if you are behind a proxy you should configure the max allowed size of attachments.


No, we're sitting inside the same network firewall as the instance.

It appears there was a session limit by default within IIS7 which was set to 30,000,000 bytes. We ameneded this so that we could upload files up to 100mb in size and it now works fine.

Thanks all for the help.

Suggest an answer

Log in or Sign up to answer
How to earn badges on the Atlassian Community

How to earn badges on the Atlassian Community

Badges are a great way to show off community activity, whether you’re a newbie or a Champion.

Learn more
Community showcase
Published Thursday in Jira

5 ways you can make the most of Jira Software and Bitbucket Cloud

As part of the Bitbucket product team I'm always interested in better understanding what kind of impact the use of our tools have on the way you work. In a recent study we conducted of software devel...

63 views 0 5
Read article

Atlassian User Groups

Connect with like-minded Atlassian users at free events near you!

Find a group

Connect with like-minded Atlassian users at free events near you!

Find my local user group

Unfortunately there are no AUG chapters near you at the moment.

Start an AUG

You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs

Groups near you