XF 1.4 Forum display corrupting

I've just started the process of migrating my fairly small vBulletin 3.8 forum to XenForo. This is my first XenForo install, and I’ve hit a problem with permissions.

I noticed it after some of my users imported with permissions that aren't quite right. I can correct the permissions problem and get it all working, but there's an underlying problem that needs correcting before I can go any further.

When a user tries to view something they don’t have permission for, the forum display just corrupts like this:

To try and boil the problem down to the basics, I’ve done a new install with nothing imported, no add-ons installed, no styling and nothing changed in the Admin CP.

I created a new user though the front-end, made a single post, and it all worked OK.

I then log in as an Admin and remove the View permission from the User Group, and the user gets a corrupted screen as above when they next log in. If I change the permissions back, it works correctly again.

I’ve tried exactly the same thing using XenForo’s demo on their website, and that handles it correctly, showing a message saying “You do not have permission to view this page or perform this action” when the user without the correct permissions logs in.

I guess I’m either making a basic mistake with the install, or there’s something at server level not working as it should.

Any suggestions how I can go about locating the problem?


It shows a correctly formatted page, with exactly the same error message as with the link you've posted.

I've tried re-installing a few times now and I've got the same result each time, so I must be doing something wrong.

Other than the strange corrupted page when permissions are changed, it all seems to work correctly.

It does seems very odd. I'll come back to it tomorrow after a good sleep and start from scratch, I'm probably doing something really stupid!


XenForo moderator
Staff member
I doubt it's anything you are doing, it's more likely server related.

What is your server set up?
Is it a typical install or is there anything particular about it?
Any caching implemented?
I'm installing this forum onto a basic shared hosting package with StableHost (the same way as I run my current vBulletin forum that I'm migrating).

StableHost use XenForo for their own customer forum - I'll drop them an email and ask if they're aware of anything that could be affecting the install.


XenForo moderator
Staff member
One other thing you could try (although I doubt it would change it), is downloading a new .zip from your customer area and uploading the files, overwriting what is already on the server.

That should rule out any issues with corruption of the XF files.
I've uploaded the files a couple of times now, but I'm using the same downloaded copy, so I'll give that a try as well - it's worth at least ruling it out.



Well-known member
I've seen this before when compression is turned on and configured wrong. It happens a lot on shared servers that have too many sites on them. Normally it only affects users of Internet Explorer although I have seen older versions of Firefox render a page the same way.
Thanks for the suggestion. I've just tried it on a few different browsers, including the latest versions of Firefox and Chrome, and they all display the same behaviour.

I'm now following it up with my hosting provider to see if they can find any issues.
I've followed up on everything suggested in this thread, and something Brogan mentioned earlier has led me to the source of the problem.

My hosting provider has implemented server-side caching on the shared hosting package using Varnish. If I switch it off, XenForo works correctly.

I have no knowledge or experience of caching, but I can only presume that the way my host has set it up is somehow incompatible with XenForo?

Anyway, thanks for the help, I can get on with my migration away from vBulletin now!