Notes From the Field: Finding and Remediating EWS App Usage Before Retirement

Not sure what to say, I seem to be getting successful lookups minus the one. It does open a browser window and asks for my login and I receive the "Authentication complete. You can return to the application. Feel free to close this browser tab." message.

.\Find-EwsUsage.ps1 -OutputPath C:\Users\Username\Desktop\EWS-Output\ -OAuthClientId {myClientID} -OAuthTenantId {myTenantID} -PermissionType Delegated -Operation GetEwsActivity -Verbose

Successful:

VERBOSE: Calling Invoke-GraphApiRequest                                                                                 
VERBOSE: Graph API uri called: https://graph.microsoft.com/v1.0/servicePrincipals(appId='24e92c11-071d-4be6-83d1-66b18f8ef1cc')/appRoleAssignments
VERBOSE: Method: GET ContentType: application/json                                                                      
VERBOSE: Calling Invoke-WebRequestWithProxyDetection                                                                    
VERBOSE: Calling Confirm-ProxyServer                                                                                    
VERBOSE: Proxy server configuration detected                                                                            
VERBOSE: Unable to check for proxy server configuration                                                                 
VERBOSE: WebRequest: v1.1 GET https://graph.microsoft.com/v1.0/servicePrincipals(appId='24e92c11-071d-4be6-83d1-66b18f8ef1cc')/appRoleAssignments with application/json payload with body size 0 b (0 bytes)
VERBOSE: WebResponse: 200 OK with application/json payload                                                              
VERBOSE: Graph API request successful   

The below is the only unsuccessful lookup, but it's not saying why:

VERBOSE: Calling Invoke-GraphApiRequest                                                                                 
VERBOSE: Graph API uri called: https://graph.microsoft.com/v1.0/servicePrincipals(appId='d1b9d202-4d99-4012-938a-31c08c68051c')/appRoleAssignments
VERBOSE: Method: GET ContentType: application/json                                                                      
VERBOSE: Calling Invoke-WebRequestWithProxyDetection                                                                    
VERBOSE: Calling Confirm-ProxyServer                                                                                    
VERBOSE: Proxy server configuration detected                                                                            
VERBOSE: Unable to check for proxy server configuration                                                                 
VERBOSE: WebRequest: v1.1 GET https://graph.microsoft.com/v1.0/servicePrincipals(appId='d1b9d202-4d99-4012-938a-31c08c68051c')/appRoleAssignments with application/json payload with body size 0 b (0 bytes)
VERBOSE: WebResponse: 404 Not Found with application/json payload                                                       
InvalidOperation: Find-EwsUsage.ps1:759:9
Line |                                                                                                                  
 759 |          $reader = New-Object System.IO.StreamReader($response.GetResp …                                         
     |          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                                           
     | Method invocation failed because [System.Net.Http.HttpResponseMessage] does not contain a method named 'GetResponseStream'.
VERBOSE: Graph API request failed - no response                                                                         
Unable to get app role assignments for application Teams Bot. Please review the error message below and re-run the script:
                                                                                                                        

So, it appears to be able to do all the lookups it needs to do, but is failing on the one app registration, and somehow that is causing the entire script to fail?