I keep hitting a road block when importing an iso into virtual box

The ISO came prepackaged from an instructor so, all I had to do was download the source, double click the file and import into virtual box. I also had to make a network adjustment (NAT) but, that's it. I have been having some problems with V-Box running slow using this same Virtual Machine. This process has been successful previously (Installation wise. I deleted and re-installed this same Virtual Machine twice to fix some issues). Any help in helping me understand why this error is now occurring would be greatly appreciated. Thank You.

Failed to open a session for the virtual machine Kali 2020 x64 Customized by zSecurity v1.2.

VMMR0_DO_NEM_INIT_VM failed: VERR_NEM_MISSING_KERNEL_API_2 (VERR_NEM_MISSING_KERNEL_API_2).

VT-x is not available (VERR_VMX_NO_VMX).

Result Code: E_FAIL (0x80004005)
Component: ConsoleWrap
Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed}