Changes have been made in Git for this ticket:

Bug #9162: Fix logintasks confirmation page.

http://git.horde.org/diff.php/horde/services/logintasks.php?rt=horde-git&r1=f1a520a5003e419b985f41662e6188b441a4814f&r2=9f938e61dbad2367a5a220489ed5bafde394dea3

When navigating TO an application, such as Kronolith, that has 
logintasks to run FROM the link in the (d)imp sidebar, a fatal error 
is thrown:

A fatal error has occurred
Do not directly access logintasks.php.

Details
The full error message is logged in Horde's log file, and is shown 
below only to administrators. Non-administrative users will not see 
error details.

Horde_Exception Object
(
     [message:protected] => Do not directly access logintasks.php.
     [string:Exception:private] =>
     [code:protected] => 0
     [file:protected] => /horde/horde/horde/services/logintasks.php
     [line:protected] => 19
     [trace:Exception:private] => Array
         (
         )

     [previous:Exception:private] =>
     [xdebug_message] => <tr><th align='left' bgcolor='#f57900' 
colspan="5"><span style='background-color: #cc0000; color: #fce94f; 
font-size: x-large;'>( ! )</span> Horde_Exception: Do not directly 
access logintasks.php. in /horde/horde/horde/services/logintasks.php 
on line <i>19</i></th></tr>
<tr><th align='left' bgcolor='#e9b96e' colspan='5'>Call Stack</th></tr>
<tr><th align='center' bgcolor='#eeeeec'>#</th><th align='left' 
bgcolor='#eeeeec'>Time</th><th align='left' 
bgcolor='#eeeeec'>Memory</th><th align='left' 
bgcolor='#eeeeec'>Function</th><th align='left' 
bgcolor='#eeeeec'>Location</th></tr>
<tr><td bgcolor='#eeeeec' align='center'>1</td><td bgcolor='#eeeeec' 
align='center'>0.0002</td><td bgcolor='#eeeeec' 
align='right'>325604</td><td bgcolor='#eeeeec'>{main}(  )</td><td 
title='/horde/horde/horde/services/logintasks.php' 
bgcolor='#eeeeec'>../logintasks.php<b>:</b>0</td></tr>

)


To reproduce:

Ensure a login task is set to run for the next login to Kronolith.
Login to Horde.
Navigate to (d)imp if it's not the default application.
Accept any login tasks for imp.
Navigate to Kronolith by using the Calendar link in the sidebar.