Error- Type "UiPath.Excel.WorkbookApplication" cannot be serialized

I am getting this error - Type “UiPath.Excel.WorkbookApplication” cannot be serialized.
if i delete “Delay” duration activities steps from the workflow then it works fine. but i need to use “Delay” in the workflow. I am not sure how come delay activity is related with UiPath excel workbook application and causing an error. i have used “Delay” activity in my other RPA programs but never got this error.
Please help me to find out which steps is causing this error

error: Type ‘UiPath.Excel.WorkbookApplication’ cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. Alternatively, you can ensure that the type is public and has a parameterless constructor - all public members of the type will then be serialized, and no attributes will be required.

The image shows an error message from UiPath indicating that the type 'UiPath.Excel.WorkbookApplication' cannot be serialized and suggests using the DataContractAttribute and DataMemberAttribute attributes, or ensuring the type is public with a parameterless constructor for serialization. (Captioned by AI)

Can you provide the workflow in which you use this activity? I’ll see if I can replicate the issue

Hİ, @Purva

Change the activity package from manage packages.

İf error continu use the excel application scope read or write range

@Purva,

This could be the root cause.

Check if you are passing in Excel scope through Arguments.