Avast has quarantined the file which prevents Radar from starting.
Open the virus chest
In the Status window add an action icon or right click on one that is already there, select add or change short-cut and select virus chest in the list.
Now click on the newly created Virus Chest icon then right click on the file XM8DLL.dll and select Restore and Add to Exclusions.
If the file remains in the Virus Chest despite this action, in the menu on the left of the Status window click on Settings
In the sub-menu click on Anti-Virus and on the right hand side scroll down to Exclusions
Click on the Browse button and browse to C, click on the cross to open the list of sub-folders and then tick the box next to Radar.
Click on OK then click on Add and then on OK at the bottom of the window.
Close Avast
Now disable Avast for 10 minutes: in the system tray at the bottom right-hand corner of your computer screen click on the small arrow head to show the hidden icons
Right click on the Avast icon
Click on Avast Shields Control then disable for 10 minutes
Click here and save the XM8DLL file in the folder C:\Radar\Bin and then start Radar.