ThinApp User’s Guide : Configuring Package Parameters : Configuring Dependent Applications with Application Link : OptionalAppLinks

OptionalAppLinks
The OptionalAppLinks parameter is similar to the RequireAppLinks parameter but ignores errors and starts the main application even when an import operation fails.
You must create a link to the primary data container of a package. You cannot link to other shortcut packages.
Path names are on the deployment machine because the linking takes effect at runtime on the client machine. You can specify absolute paths, such as C:\abs\path\dotnet.exe, relative paths, such as relpath\dotnet.exe, and UNC paths, such as \\server\share\dotnet.exe.
RequiredAppLinks and OptionalAppLinks parameters use the same syntax. For information about the RequireAppLinks parameter and examples, see RequiredAppLinks.