Revert "Added new post"

This reverts commit 17f89f5.

Author: Daniele Catanesi

_posts/2022-01-25-Cannot bind argument to parameter-Token-Expiry.md

@@ -1,46 +1,57 @@
 ---
-title: "PowerShell - Get day of weekday"
-excerpt: "In this short post we will see how we can use PowerShell to get an integer representing the number associated with the day of the week for the current date."
+title: "Cannot bind argument to parameter TokenExpiryTime because it is null - Error Message"
+excerpt: "When opening a PowerShell session to both on-prem and Exchange online in the same window cannot bing argument to parameter TokenExpiryTime because is null error message could be displayed. Let's explore how to solve this."
 categories:
   - PowerShell
-  - Howto
+  - Exchange
+  - Office 365
 
 tags:
   - PowerShell
-  - Tips
-  - HowTo
+  - Office365
+  - Exchange
 
 toc: true
 header:
   teaser: "/assets/images/PowerShell_Logo.png"
 ---
 
-## PowerShell Get current date
+## Exchange Online Certificate Based authentication
 
-PowerShell natively supports getting the current, or specific, date via the following cmdlet:
+Microsoft is, _finally_, disabling **basic authentication** (read username and password) in Exchange Online in favor of **Certificate Based authentication**.
 
-```powershell
-Get-Date
-```
-Which, by default, will produce the following output:
+Once this change is fully implemented, around mid February at least for some tenants, connecting via username and passwords to Exchange Online will not be possible anymore.
 
-```powershell
-Monday, February 21, 2022 10:11:39 PM
-```
+You can read my article on how to implement _Certificate Based authentication_ for Exchange Online [here](https://pscustomobject.github.io/powershell/office365/exchange/Exchange-Online-Certificate-Based-Authentication/).
 
-Cmdlet supports methods which can be used to display/return the day of the week for the selected date
+As a result of this change I started updating one of our automations, responsible for the whole life-cycle of our mailboxes, to ditch old credential objects in favor of the more secure Certificate Authentication.
 
-```powershell
-(Get-Date).DayOfWeek
-```
+This is when I encountered the _cannot bind argument to parameter 'token expiry time' because it is null._ error message.
+
+## Multiple PowerShell Exchange Sessions
 
-There are situations where rather than returning a string with the day name it can be useful to return the **number** (1 to 7) associated with the day's name, this can easily be accomplished with the following command
+When operating an hybrid environment it is pretty common to open, in the same window/session, a PowerShell connection to both Exchange on-prem and Exchange Online.
+
+This is required as part of the configuration, usually creation of the mailbox, takes place in on-prem for example via the _New-RemoteMailbox_ cmdlet while other parts of the configuration are performed directly online for example when delegating mailbox permissions. 
+
+While debugging my workflow I have noticed that, while trying to retreive mailbox information from the on-prem server, an exception was being thrown
 
 ```powershell
-(Get-Date).DayOfWeek.value__
+# Cmdlet I was running
+Get-RemoteMailbox -Identity $userUpn
 
-# Output
-1
+# Part of the exception message
+Cannot bind argument to parameter 'token expiry time' because it is null.
 ```
 
-This is specially handy when inserting data into SQL datbase supporting dates as *TinyInt* data types.
+It took me a bit to figure this out as no exception was thrown during the connection *phase* either nor there was any other obvious pointer.
+
+When I was about to give up and open a ticket with Microsoft, which is usually as helpful as freezer in the North Pole, I discovered that establishing a connection to Exchange Online followed by a connection to the on-prem server was yielding the desired result. In my workflow I had this the other way around, first local Exchange and then Online service, which was causing the issue.
+
+**Note:** I have experienced/tested this with version 2.0.4 and 2.0.5 of Exchange Online PowerShell module but other versions could be affected as well.
+{: .notice--warning}
+
+I did not dig deep into the root cause of the issue but plan to do this tomorrow and already sent my feedback to exocmdletpreview {at} service {dot} microsoft {dot} com but I doubt I will hear anything from that channel. 
+I will anyhow open a ticket with support to at least have an official statement/clarification on this.
+
+As soon as I have any news I will update the post until then I hope you can find the information useful.