“SIMBLAgent.app“ wants access to control

These messages are part of the new security measures in Mojave. You are giving up control of your system to apps you may not intend, so you should deny those requests until you’re sure it is not malware or something you don’t want typing / interacting on your behalf.

Consider, an app could copy text like passwords or just watch for you typing / save screen captures using these permissions. Not all do, but you might use caution before disabling security.

You can try giving the app full disk access in the System Preferences.app > Security & Privacy > Privacy > Full Disk Access. Add the application by using the [+] icon or by dragging to the list.

As per Gummibando's answer, you'll need to give permissions to SIMBLAgent.app in Security & Privacy in preferences:

The full path to the app should be:

/Library/Application Support/SIMBL/SIMBLAgent.app

However, it appears Automation is the correct category: