[Koha] Error in Koha Plugin

[Sahadeo Taware]

I want to use Koha Plugin
I have done all the setting required to enable the koha plugins
But when I go to tools > plugins it give following error

Software error:

Undefined subroutine &main::/var/lib/koha/library/plugins called at
(eval 61) line 2.
	...propagated at /usr/share/perl/5.18/base.pm line 83.
BEGIN failed--compilation aborted at
/usr/share/perl5/Authen/CAS/Client/Response.pm line 68.
Compilation failed in require at /usr/share/perl5/Authen/CAS/Client.pm line 8.
BEGIN failed--compilation aborted at
/usr/share/perl5/Authen/CAS/Client.pm line 8.
Compilation failed in require at
/usr/share/koha/lib/C4/Auth_with_cas.pm line 25.
BEGIN failed--compilation aborted at
/usr/share/koha/lib/C4/Auth_with_cas.pm line 25.
Compilation failed in require at /usr/share/koha/lib/C4/Auth.pm line 62.
BEGIN failed--compilation aborted at /usr/share/koha/lib/C4/Auth.pm line 89.
Compilation failed in require at
/usr/share/koha/intranet/cgi-bin/plugins/plugins-home.pl line 26.
BEGIN failed--compilation aborted at
/usr/share/koha/intranet/cgi-bin/plugins/plugins-home.pl line 26.

For help, please send mail to the webmaster ([no address given]), giving
this error message and the time and date of the error.


Kindly help me to solve the error

-- 
Sahadeo D. Taware
Librarian, M.L.I.Sc., NET
Thakur College of Science and Commerce
Thakur Village, Kandivli(E), Mumbai 400101
Mob. No 9324912816
Office 28870627 Extn. 126