[horde] Problem synchronizing his calender

[Ruud Baart]

Hi,

one of my users has a problem with synchronizing his calender. He is the 
only one as far as I know. He has an inscription on several calenders. 
It always worked but after a crash of his Windows notebook (driver 
problems, blue screens etc) and a partial reinstall of Windows 10 he 
can't synchronize his agendas.

He uses Thunderbird with Lightning. I reinstalled it for him after the 
crash. But it won't work. The error in the logfile in Horde is:

EMERG: HORDE [kronolith] Call to a member function toHash() on boolean 
[pid 5210 on line 696 of "/....../kronolith/lib/Application.php"

I think, but I'm not sure, it has something to do with his notebook. On 
another computer I can access with Thinderbird and Lightning his calender.

I'm not sure where to look. Is it something with the data of this user 
in combination with his hardware? Is his notebook sending wrong data to 
Kronolith?

Horde framework is up to date, server is Debian jessie, php version 5.6.33.

-- 

Cordialement,
R.J. Baart