The variable field cannot be edited, not only the default value, but also the variable type. But I can still add or delete the activity and edit the properties of each activity. Very weird. This issue appeared since few days ago, restart PC is not helping it.
My PC/software information as follow.
UiPath Studio 2017.1.6522 \ OS Version: Win 7 Professional 64-bit \ .NET 4.0.30319.42000
Anyone has idea please share with me. Thanks.