[Koha] Plugin Error

[SATISH]

Hi,

With Lubuntu 16.04 LTS + Koha 18.11.05 + MySQL + Installation by Package
Method

Still I am not able to upload plugins to Koha

Throws the same error:
*--*

*Cannot unpack file to the plugins directory.Please verify that the Apache
user can write to the plugins directory.*
--
I tried permission with all possible names suggested in the reply ( like,
www-data, koha-instance, root) , but no success.

Can you please help me get this fixed?

With thanks.
Satish MV
Librarian
Govt. Engineering College, Hassan
Karnataka