I installed the Electronics theme and everything went as expected...
Thank you for using our products!
From the Administration set the setting below:
General And Miscellaneous Settings -> Security Settings -> Hide admin menu items based on permissions
This is needed in order to get the Plugins menu appear otherwise it is not shown and you won't be able to configure the plugins.
We have reported this problem, which was introduced in nopCommerce 2.4 and it will be fixed by the nopCommerce team in version 2.5.
Please note that we automatically set this setting in the installation of the Core plugin, so there might be some problem with your installation.
Please let us know if you have any more problems with the theme\plugins!
Nop-Templates Support Team