This problem is not related with our theme. There are several cause in this problem.
Please look this article.
We think this problem is caused by your hosting server. If you install your wordpress site via your hosting server, they can manage to disable/enable theme & plugins.
You can't only add or remove plugins, but also themes. Please contact your hosting server provider.
If you have other questions, please let us know again.
Best Regards, C-Themes