ProcessTransaction workflow error: Value cannot be null. Parameter name: expression

Hello!
Hit below error on my Process.xaml workflow, is there any could helping to take a look?
image

log message:
18.4.5+Branch.support/v2018.4.Sha.2a53a262e2c1098055c3ecbdabe73d45e0a6dc29

The workflow has validation errors. Review and resolve them first.

System.ArgumentNullException: Value cannot be null.
Parameter name: expression
at System.Activities.InArgument1.FromExpression(Activity1 expression)
at System.Activities.InArgument1.op_Implicit(Activity1 expression)
at UiPath.Core.Activities.OnWaitActivity.<>c__DisplayClass21_0.<.ctor>b__0()
at System.Activities.Activity.OnInternalCacheMetadata(Boolean createEmptyBindings)
at System.Activities.Activity.InternalCacheMetadata(Boolean createEmptyBindings, IList1& validationErrors) at System.Activities.ActivityUtilities.ProcessActivity(ChildActivity childActivity, ChildActivity& nextActivity, Stack1& activitiesRemaining, ActivityCallStack parentChain, IList1& validationErrors, ProcessActivityTreeOptions options, ProcessActivityCallback callback) at System.Activities.ActivityUtilities.ProcessActivityTreeCore(ChildActivity currentActivity, ActivityCallStack parentChain, ProcessActivityTreeOptions options, ProcessActivityCallback callback, IList1& validationErrors)
at System.Activities.ActivityUtilities.CacheRootMetadata(Activity activity, LocationReferenceEnvironment hostEnvironment, ProcessActivityTreeOptions options, ProcessActivityCallback callback, IList`1& validationErrors)
at System.Activities.Validation.ActivityValidationServices.InternalActivityValidationServices.InternalValidate()
at System.Activities.Validation.ActivityValidationServices.Validate(Activity toValidate, ValidationSettings settings)
at System.Activities.Presentation.Validation.ValidationService.CoreValidationWork(ValidationReason reason, CancellationToken cancellationToken)

Process.xaml (11.5 KB)

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Hi. Please read this post:

Thanks :slight_smile:

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Thanks for your comments, I have try but cannot figure out the root cause… Could you please take a look my Process.xaml file?

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Sure!

HI, I am also facing the same error. How to resolve this issue?