CertificateAssistant_v3 Fehler: ERROR - Can't order certificate: You cannot call a method on a null-valued expression

Hallo zusammen!

Vielen Dank für das super Script des CertificateAssistant, das wir unter Exchange 2016 einsetzen. Ich hab die Version v3 nun einige Jahre genutzt, heute ging es aber plötzlich nicht mehr durch. Eine Änderung im Script ist definitiv auszuschließen, wir haben das seit Jahren nun unbearbeitet gelassen und es ging immer.

Dabei taucht nun folgende Fehlermeldung auf:

PS C:\Users\Administrator\Documents\CertificateAssistant_v3\LetsEncrypt\Exchange 2016> C:\Users\Administrator\Documents\CertificateAssistant_v3\LetsEncrypt\Exchange 2016\CertificateAssistant_v3_EX2016.ps1
25.07.2025 11:24:08 - System - Info - Geting system parameters
25.07.2025 11:24:08 - System - Info - Certificate Assistant Exchange 2016 Version
25.07.2025 11:24:08 - System - Info - PowerShell Version: 5.1.14409.2001 OSVersion: 6.3.9600.0
25.07.2025 11:24:08 - Check Posh-ACME - Info - Check if Module installed
25.07.2025 11:24:08 - Load Posh-ACME - Info - Posh-ACME is installed, try to load it
25.07.2025 11:24:09 - Load Posh-ACME - Info - Module Import was successfull, PoshACMEVersion 3.13.0
25.07.2025 11:24:09 - Load Exchange SnapIns - Info - Try to load Exchange SnapIns
25.07.2025 11:24:10 - Load Exchange SnapIns - Info - Sucessfully loaded Exchange SnapIns
25.07.2025 11:24:10 - IIS - Info - Trying to create .Well-Known Directory
25.07.2025 11:24:10 - IIS - Info - Well-Known Folder already exists, skipping
25.07.2025 11:24:10 - IIS - Warning - Mime Type was not added to Well-Known folder, maybe it was al
ready added
25.07.2025 11:24:10 - IIS - Info - Changing Let's Encrypt IIS directory to http
25.07.2025 11:24:10 - IIS - Info - Successfully changed Let's Encrypt IIS directory to http
25.07.2025 11:24:10 - IIS - Info - Checking Let's Encrypt IIS directory to accept validation by htt
p request
25.07.2025 11:24:10 - IIS - Info - .well-known directory accepts http
25.07.2025 11:24:10 - Custom FQDNs - Info - Using Custom FQDNs is configured
25.07.2025 11:24:10 - LE System - Info - Setting LE Mode
25.07.2025 11:24:10 - LE System - Info - Setting LE Mode to PRODUCTION MODE (LIVE SYSTEM)
25.07.2025 11:24:10 - LE System - Info - Checking for existing LE Account
25.07.2025 11:24:10 - LE System - Info - Found a existing LE Account
25.07.2025 11:24:10 - LE Certificate - Info - Trying to create a new order for a certificate
25.07.2025 11:24:11 - LE Certificate - ERROR - Can't order certificate: You cannot call a method on
a null-valued expression.
25.07.2025 11:24:11 - LE System - Info - Creating Autorisation files for LE verification
Get-PAAuthorizations : Cannot bind argument to parameter 'AuthURLs' because it is null.
At C:\Users\Administrator\Documents\CertificateAssistant_v3\LetsEncrypt\Exchange 
2016\CertificateAssistant_v3_EX2016.ps1:501 char:21
+ $auths = $LEOrder | Get-PAAuthorizations
+ ~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (:) [Get-PAAuthorizations], ParameterBindingValidation 
Exception
+ FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Get-PAAuthorizations
25.07.2025 11:24:11 - LE System - Info - Asking LE to verify the order
Send-ChallengeAck : Cannot bind argument to parameter 'ChallengeUrl' because it is an empty 
string.
At C:\Users\Administrator\Documents\CertificateAssistant_v3\LetsEncrypt\Exchange 
2016\CertificateAssistant_v3_EX2016.ps1:517 char:21
+ $auths.HTTP01Url | Send-ChallengeAck
+ ~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (:) [Send-ChallengeAck], ParameterBindingValidationExc 
eption
+ FullyQualifiedErrorId : ParameterArgumentValidationErrorEmptyStringNotAllowed,Send-Challeng 
eAck
25.07.2025 11:24:11 - LE System - Info - Successfully informed LE to verify the order
25.07.2025 11:24:11 - LE System - INFO - Let's give LE some time to validate (1 min)
25.07.2025 11:25:11 - LE System - INFO - Time to wake up, need coffee!
25.07.2025 11:25:11 - LE System - INFO - Let's check the authorization
Get-PAAuthorizations : Cannot bind argument to parameter 'AuthURLs' because it is null.
At C:\Users\Administrator\Documents\CertificateAssistant_v3\LetsEncrypt\Exchange 
2016\CertificateAssistant_v3_EX2016.ps1:540 char:27
+ $authstates = $LEOrder | Get-PAAuthorization
+ ~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (:) [Get-PAAuthorizations], ParameterBindingValidation 
Exception
+ FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Get-PAAuthorizations
25.07.2025 11:25:11 - LE System - INFO - Let's refresh the order
25.07.2025 11:25:11 - LE System - INFO - Let's check if order is ready
25.07.2025 11:25:11 - LE System - ERROR - Order is NOT ready
PS C:\Users\Administrator\Documents\CertificateAssistant_v3\LetsEncrypt\Exchange 2016>

Aufgrund meiner fehlenden Powershell-Kenntnisse bin ich leider komplett ratlos. Außerdem die Frage, ob das Problem bei sonst noch wem auftritt.

Danke!