ReportUnusedExoMailboxes.PS1 "System.DateTime". Error: "String was not recognized as a valid DateTime." about office365itpros HOT 5 CLOSED

Get-Date : Cannot bind parameter 'Date'. Cannot convert value "7/18/2023 5:01:47 AM" to type "System.DateTime". Error: "String was not recognized as a valid DateTime."
At C:\ReportUnusedExOMailboxes.PS1:34 char:50
+         [datetime]$LastActiveDateTime = Get-Date $LastActive
+                                                  ~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Get-Date], ParameterBindingException
    + FullyQualifiedErrorId : CannotConvertArgumentNoMessage,Microsoft.PowerShell.Commands.GetDateCommand
 
New-TimeSpan : Cannot bind parameter 'Start' to the target. Exception setting "Start": "Cannot convert null to type "System.DateTime"."
At C:\ReportUnusedExOMailboxes.PS1:35 char:49
+ ...   $DaysSinceActive = (New-TimeSpan -Start $LastActiveDateTime -End $N ...
+                                               ~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : WriteError: (:) [New-TimeSpan], ParameterBindingException
    + FullyQualifiedErrorId : ParameterBindingFailed,Microsoft.PowerShell.Commands.NewTimeSpanCommand
 

PS C:\Windows\system32\WindowsPowerShell\v1.0>  $LastActive
7/18/2023 5:01:47 AM

PS C:\Windows\system32\WindowsPowerShell\v1.0> $LastActiveDateTime

PS C:\Windows\system32\WindowsPowerShell\v1.0> (New-TimeSpan -Start $LastActiveDateTime -End $Now).Days
New-TimeSpan : Cannot bind parameter 'Start' to the target. Exception setting "Start": "Cannot convert null to type "System.DateTime"."
At line:1 char:22
+ (New-TimeSpan -Start $LastActiveDateTime -End $Now).Days
+                      ~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : WriteError: (:) [New-TimeSpan], ParameterBindingException
    + FullyQualifiedErrorId : ParameterBindingFailed,Microsoft.PowerShell.Commands.NewTimeSpanCommand