[Koha] Koha search error

[Dibyendra Hyoju]

Hi all,

Just recently after upgrading the Koha from 3.14 to 3.16 we have been
facing following problem when certain keywords are used during the search
like: account, business, accounting, financial, financial accounting, etc.
Earlier there were no such problems. But when I search other keywords apart
from the mentioned keywords, there are no problems. Has anyone faced this
kind of problem and found a solutions already? Any help would be
appreciated. Thanks.
Software error:

Can't call method "as_string" on an undefined value at
/usr/share/koha/lib/C4/Koha.pm line 1608.

Regards,
Dibyendra Hyoju