Urgent Problem - Internal Error 500 on pages in admin

[TimAllen]

Hi everyone. I have a weird new problem. I have built dozens of sites in CMSMS and found it terrific. One one site, http://www.eastcoastmarineservices.co.uk when logged in as admin with full permissions, I have lost the 'Pages' section at http://www.eastcoastmarineservices.co.u ... _=07cd2450

Every other section works as normal, inc file manager, templates and stylesheets.

I just get HTTP 500 Internal Server error. I'm on Heart Internet on 1.11 Baltra, for this site. (Each site gets CMSMS installed seperately, so you dont upgrade unless you dump de-install and re-install)

update: Still locked out of pages, but in Chrome I get a blank page with this as the source:
<!-- OneEleven::ShowErrors() called --><div class="pagecontainer">
<div class="pageoverflow"></div>

Any ideas?

Thanks!

[TimAllen]

Update - solved.
Bizarre, but changing the back end UI to NCleanGrey then back to OneEleven seems to have cured it - for now....? Happy days!