Fatal error: Call to undefined function deactivate_plugins()

[arena]

Fatal error: Call to undefined function deactivate_plugins()

plugin test case and image of result

You've got a error in your code.

You're only deactivating upon the error scrape, Not on the activation hook.

(You should deactivate in the activation hook, NOT the error scrape stuff, The deactivate_plugins() function error is due to the plugin being activated on the activate call, and the error scrape code being run when the active plugins are included.)