The type or namespace name 'Xml' does not exist in the namespace 'System.Security.Cryptography'

@chirag.joban05

Close the XAML
Close UiPath / Project
Take a backup from the XAML
Open the XAML within a text editor (e.g. notpad++)
Add the Assembly reference in case of it is missing:
grafik
<AssemblyReference>System.Security.Cryptography.Xml</AssemblyReference>

Save the file
Open studio and try again. Now the Class and namespace should be recognized

Maybe do the same for <AssemblyReference>System.Security.Cryptography</AssemblyReference>

and ensure that the invoke code is correct and do not use unneeded / unsupported statements