Persistent error with Newtonsoft.Json.JsonReaderException - json

Question

I have been attempting to run commands from the AzureAD powershell module, but I am consistently getting Json errors.
The issue is so persistent no matter what commands I run, I am wondering if the Newtonsoft.Json package is misconfigured and needs to be reinstalled.
Example:
New-AzureADServiceAppRoleAssignment -Id "any id" -ResourceId "any id" -ObjectId "any id" -PrincipalID "any id"
Output:
Error reading JToken from JsonReader. Path '', line 0, position 0
At line:1 char:1
New-AzureADServiceAppRoleAssignment -Id ....
CategoryInfo : NotSpecified: (:) [New-AzureADServiceAppRoleAssignment], JsonReaderException
FullyQualifiedErrorId: Newtonsoft.Json.JsonReaderException.Microsoft.Open.AzureAD16.Powershell.NewServicePrincipalAppRoleAssignment.

Answer 1

I tried in my environment and got successfully created a new app role service principal assignments:
Commands:
Connect-AzureAD
New-AzureADServiceAppRoleAssignment -ObjectId $servicePrincipal.ObjectId -PrincipalId $servicePrincipal.ObjectId -ResourceId $resourceApp.ObjectId -Id $permission.Id
Console:
Portal:
Make sure you are using latest version of Newtonsoft.json.
if you are using lower version, try to uninstall and reinstall the latest version by below command:
Install-Module -Name newtonsoft.json -RequiredVersion 1.0.1.2
If the error is still persisting uninstall AzureAD module reinstall the AzureAD-Module confirm all the traffic can be passed the network policy (Firewall) .
Verify if you are using the latest version of Azure AD PowerShell module? Also, validate if your local machine's firewall is restricting the command? Or if you're connected to any VPN or organizational laptop.
If AzureAD module is already installed, Install new version(2.0.2.140).
Command:
Install-Module -Name AzureAD --Allowclobber
Reference:
Getting error when running script · Issue #2 · adrecon/AzureADRecon (github.com)