Having backtracked my changes this evening I realised that the account I am using for this web site was over quota. Have reset it in whm to unlimited and now all is fine.
Once you use the page next/previous in the footer of a list and then try and edit a record the error occurs.
To get around this problem I have changed line 2205 in data_report/class.php
from
$PageLink = ‘admin.php?page=’ . $_GET[‘page’] . ‘&sub=’ . $Config[‘_ItemViewInterface’] . ‘&’ . htmlspecialchars_decode(http_build_query($ReportVars));
to
$PageLink = ‘admin.php?page=dbt_builder&renderinterface=’ . $Config[‘_ItemViewInterface’] . ‘&’ . htmlspecialchars_decode(http_build_query($ReportVars));
