Error: no provider exists with the given name

[akbarahs]

This is my terraform main script

terraform {
  required_providers {
    virtualbox = {
      source = "terra-farm/virtualbox"
      version = "0.2.2-alpha.1"
    }
  }
}

provider "virtualbox" {
  # Configuration options
}

resource "virtualbox_vm" "node" {
    count = 2
    name = "${format("node-%02d", count.index+1)}"
     url = "https://vagrantcloud.com/ubuntu/boxes/xenial64/versions/20180420.0.0/providers/virtualbox.box"
    image = "./virtualbox.box"
    cpus = 2
    memory = "512 mib"
   // user_data = "${file("user_data")}"


    network_adapter {
    type = "bridged"
    host_interface="en0"
    }
}

and this where the plugins are available

PS C:\Users\Heisenberg\.terraform.d\plugins> dir
Directory: C:\Users\Heisenberg\.terraform.d\plugins
Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
d-----        13-02-2022  12:05 PM                terraform-provider-virtualbox
d-----        13-02-2022  12:05 PM                terraform-provider-virtualbox_v0.2.1
d-----        13-02-2022  12:05 PM                windows_amd64
PS C:\Users\Heisenberg\.terraform.d\plugins>

and also here

PS C:\Users\Heisenberg\AppData\Local\.terraform.d\plugins> dir
Directory: C:\Users\Heisenberg\AppData\Local\.terraform.d\plugins
Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
d-----        13-02-2022  12:05 PM                terraform-provider-virtualbox
d-----        13-02-2022  12:05 PM                terraform-provider-virtualbox_v0.2.2-alpha.1
d-----        13-02-2022  12:17 PM                windows_amd64
PS C:\Users\Heisenberg\AppData\Local\.terraform.d\plugins>

but still terraform couldnt find the plugins. I followed your beautiful answer but I am still unable to make it work. Please help a brother out.

PS E:\Practice-Terraform\VirtualBox VM> terraform init

Initializing provider plugins...
- Checking for available provider plugins...

Provider "virtualbox" not available for installation.

A provider named "virtualbox" could not be found in the Terraform Registry.

This may result from mistyping the provider name, or the given provider may
be a third-party provider that cannot be installed automatically.

In the latter case, the plugin must be installed manually by locating and
downloading a suitable distribution package and placing the plugin's executable
file in the following directory:
    terraform.d/plugins/windows_amd64

Terraform detects necessary plugins by inspecting the configuration and state.
To view the provider versions requested by each module, run
"terraform providers".


Warning: Skipping backend initialization pending configuration upgrade

The root module configuration contains errors that may be fixed by running the 
configuration upgrade tool, so Terraform is skipping backend initialization. See 
below for more information.


Error: no provider exists with the given name

Thank you

[VoyTechnology]

What is the version of Terraform that you are using? Does the error occur with the latest version of Terraform as well?