Fatal error on getting ads

I’m getting fatal error on wp Dashboard, in your “WordPress Guides/Tutorials” ads block.
http://4.stefantsov.com/s/2019.01.27_14.16.29_dtkxenuz.png

Code throwing error is $all_plugins = array_merge( $themeisle_plugins, $codeinwp_plugins ); with error “Argument #1 is not an array”.

Here is what I see when I debug it:
http://4.stefantsov.com/s/2019.01.27_14.15.35_jhi7ost0.png
Both arguments are not arrays, it’s stdClass. Because you use json_decode without parameters, it returns class object, not array. This code will never work.

Please fix asap!