Strong name validation error
This can be caused by using an out-of-date Interop file reference in the Visual Studio solution.
Make sure the latest SDK is installed, then change the Interop reference on the solution so that it points to the relevant Interop file from the appropriate SDK installation folder as detailed below.
There is only one 32-bit interop file for the STU SDK - C:\Program Files (x86)\Wacom STU SDK\COM\bin\Win32\Interop.wgssSTU.dll
All the 32-bit interops for the Signature SDK are in C:\Program Files (x86)\Common Files\WacomGSS
There is only one 64-bit interop for the STU SDK and this is C:\Program Files (x86)\Wacom STU SDK\COM\bin\x64\Interop.wgssSTU.dll
All the 64-bit interops for the Signature SDK are in C:\Program Files\Common Files\WacomGSS