I am using a script with the New_VbrFileToTapeObject cmdlet to populate a filetotape job with a specific input for quite a while (since V9). This has always worked fine. Since being upgraded to V11 it doesn't. I get a "method or operation not implemented". Did anything change for this? My script hasn't and as far as I can see from the documentation the use of the cmdlet didn't either.
Please wrap your script snippets in code tags with </> tool next time. It makes it look clearer, it also makes it much easier to copy the code and test right away. As for your issue, I tested it in my lab with v11 and it worked as expected. However, my v11 is patched with CP2, so it might be the case that something broke in v11 and got fixed later in one of our cumulative patches. Could you please share the $error[0] variable output right after you invoke the script above?
So, I re-tested it in a clean v11 environment and didn't encounter the issue you are describing. To me, it looks like an environment or installation-related problem. Some .NET assemblies could have been referenced incorrectly or else. Please submit a support case and share its id here.