ScheduledTask: Unable to enter Debug Mode

Details of the scenario you tried and the problem that is occurring

Enabling DSC debug with Enable-DSCDebug -BreakAll and then running the ScheduledTask resource returns an error:

PowerShell DSC resource MSFT_ScheduledTask failed to execute Test-TargetResource functionality with error message: Object reference not set to an instance of an object.

Verbose logs showing the problem

VERBOSE: Perform operation 'Invoke CimMethod' with following parameters, ''methodName' = Resourcetest,'className' = MSFT_DSCLocalConfigurationManager,'namespaceName'
 = root/Microsoft/Windows/DesiredStateConfiguration'.
VERBOSE: An LCM method call arrived from computer REDACTED with user sid SID REDACTED.
WARNING: [REDACTED]:                            [DSCEngine] Warning LCM is in Debug 'ResourceScriptBreakAll' mode.  Resource script processing will be stopped to wait for PowerShell script debugger to attach.
VERBOSE: [REDACTED]:                            [DSCEngine] Importing the module C:\ProgramData\PuppetLabs\puppet\cache\lib\puppet_x\dsc_resources\ComputerManagementDsc\DscResources\MSFT_ScheduledTask\MSFT_ScheduledTask.psm1 in force mode.
DEBUG: [REDACTED]:                            [DSCEngine] 
namespace ScheduledTask
{
    public enum DaysOfWeek
    {
        Sunday = 1,
        Monday = 2,
        Tuesday = 4,
        Wednesday = 8,
        Thursday = 16,
        Friday = 32,
        Saturday = 64
    }
}
VERBOSE: [REDACTED]: LCM:  [ Start  Test     ]  [[ScheduledTask]DirectResourceAccess]
VERBOSE: [REDACTED]:                            [[ScheduledTask]DirectResourceAccess] Importing the module MSFT_ScheduledTask in force mode.
WARNING: [REDACTED]:                            [[ScheduledTask]DirectResourceAccess] Resource is waiting for PowerShell script debugger to attach.  Use the following commands to begin debugging this resource script:
Enter-PSSession -ComputerName REDACTED -Credential <credentials>
Enter-PSHostProcess -Id 10792 -AppDomainName DscPsPluginWkr_AppDomain
Debug-Runspace -Id 2
VERBOSE: [REDACTED]: LCM:  [ End    Test     ]  [[ScheduledTask]DirectResourceAccess] False in 0.5150 seconds.PowerShell DSC resource MSFT_ScheduledTask  failed to execute Test-TargetResource functionality with error message: Object reference not set to an instance of an object. 
    + CategoryInfo          : InvalidOperation: (root/Microsoft/...gurationManager:String) [], CimException
    + FullyQualifiedErrorId : ProviderOperationExecutionFailure
    + PSComputerName        : localhost
 
VERBOSE: Operation 'Invoke CimMethod' complete.
VERBOSE: Time taken for configuration job to complete is 1.603 seconds

Suggested solution to the issue

See the below issue for the same problem in a different DSC module:
https://github.com/PowerShell/SqlServerDsc/issues/448

The DSC configuration that is used to reproduce the issue (as detailed as possible)

No configuration to provide

The operating system the target node is running

OsName               : Microsoft Windows Server 2016 Standard
OsOperatingSystemSKU : StandardServerEdition
OsArchitecture       : 64-bit
WindowsBuildLabEx    : 14393.3053.amd64fre.rs1_release_inmarket.190612-1836
OsLanguage           : en-US
OsMuiLanguages       : {en-US}

Version and build of PowerShell the target node is running

PSVersion                      5.1.14393.3053                                                                                                                       
PSEdition                      Desktop                                                                                                                              
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}                                                                                                              
BuildVersion                   10.0.14393.3053                                                                                                                      
CLRVersion                     4.0.30319.42000                                                                                                                      
WSManStackVersion              3.0                                                                                                                                  
PSRemotingProtocolVersion      2.3                                                                                                                                  
SerializationVersion           1.1.0.1   

Version of the DSC module that was used ('dev' if using current dev branch)

6.4.0.0

Inspect MSFT_ScheduledTask.psm1, especially Test-TargetResource, and reproduce the failure with Enable-DSCDebug -BreakAll and the ScheduledTask resource. Compare the behavior with the referenced SqlServerDsc issue. Done means the ScheduledTask resource completes debug-mode testing without the null-reference error.