When I try to download any file with IDM, it just tries to connect to the Internet and cannot start downloading, or shows some error message.

Reason. IDM is not allowed to download or run in FireWall settings. Many FireWalls check the size of application executable file that try to access the Internet. That's because a virus can replace the file with its own, and get access to the Internet. Probably when you updated IDM, its executable file size changed, and your FireWall blocked the Internet access for IDM. If you have a FireWall installed, please check that IDMan.exe file has appropriate access rights. In some cases our customers reported that they also had to set same access rights for Uninstall.exe file from IDM root folder.

Solution: Change incorrect FireWall settings. Please choose instruction for your Internet Security (FireWall) software below:

If the instructions above do not help, please try to completely uninstall your FireWall TEMPORARILY. Disabling the FireWall is not enough, because FireWall keeps blocking access even if you switch it off. After uninstalling and rebooting, check if your problem persists. If it is resolved, then the problem is definitely caused by your FireWall software. You should try to contact its developers, and ask them for a solution, or try another FireWall.