Created Unassigned: Application.GetActiveInstance throws ArgumentException "component" [20548]

From stack trace:
"System.ArgumentException was caught
HResult=-2147024809
Message=component
Source=System
StackTrace:
at System.ComponentModel.TypeDescriptor.GetDescriptor(Object component, Boolean noCustomTypeDesc)
at System.ComponentModel.TypeDescriptor.GetClassName(Object component)
at NetOffice.RunningObjectTable.GetActiveProxyFromROT(String componentName, String className, Boolean throwOnError)
at NetOffice.ExcelApi.Application.GetActiveInstance()
at ITSR2.Bricks.Excel.ExcelApp.GetRunningInstance()
InnerException: "
Do you have an idea how to solve it?