Powershell command not working when run by octopus deploy - powershell

Question

I have several steps to figure out this problem and I do't know what else to do. My end goal is to check my "app.exe" file version. when I run it on server manually both script versions work. But when Octopus runs both versions fail with different errors
Version 1:
$file = "C:\Octopus\Applications\AppStartUp\38.2.19.0\app.exe"
$fileVersion = [System.Diagnostics.FileVersionInfo]::GetVersionInfo($file).FileVersion
I get the error:
return [System.Diagnostics.FileVersionInfo]::GetVersionInfo <<<< ($file). FileVersion
+ CategoryInfo : NotSpecified: (:) [], ParentContainsErrorRecordException
+ FullyQualifiedErrorId : DotNetMethodException
Version 2:
$file = "C:\Octopus\Applications\AppStartUp\38.2.19.0\app.exe"
(Get-Command "$file").FileVersionInfo.Fileversion
Error Message
Export-ModuleMember : The Export-ModuleMember cmdlet can only be called from in side a module. At C:\Octopus\Applications\CSIS_DEV\ESG.CSIS.StartUp\38.2.19.0\deployment\clickOnceLib.ps1:35 char:20
+ Export-ModuleMember <<<< -function * -alias *
+ CategoryInfo : PermissionDenied: (:) [Export-ModuleMember], InvalidOperationException
+ FullyQualifiedErrorId : Modules_CanOnlyExecuteExportModuleMemberInsideAModule,Microsoft.PowerShell.Commands.ExportModuleMemberCommand
Get-Command : The term 'C:\Octopus\Applications\CSIS_DEV\ESG.CSIS.StartUp\38.2.19.0\ESG.CSIS.StartUp.exe' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At C:\Octopus\Applications\CSIS_DEV\ESG.CSIS.StartUp\38.2.19.0\deployment\clickOnceLib.ps1:32 char:24
+ return (Get-Command <<<< "$file").FileVersionInfo.Fileversion
+ CategoryInfo : ObjectNotFound: (C:\Octopus\Appl...SIS.StartUp.exe:String) [Get-Command], CommandNotFoundException
+ FullyQualifiedErrorId : CommandNotFoundException,Microsoft.PowerShell.Commands.GetCommandCommand
Any Insite to these messages and why it happens only when running in octopus would be great.

Answer 1

It looks like your script can't access the file, or it doesn't exist. Check to make sure C:\Octopus\Applications\CSIS_DEV\ESG.CSIS.StartUp\38.2.19.0\ESG.CSIS.StartUp.exe exists and is accessible to the user the tentacle runs under (use windows effective permissions).
Also make sure it's there by the time the script runs, you haven't mentioned whether this is a seperate step, PreDeploy.ps1, Deploy.ps1 or PostDeploy.ps1 script