"Cannot marshal" error affecting multiple plugins. Please, help!

I’m completely stuck. I’m getting the following error:

  1. Solution exception:Cannot marshal ‘parameter #5’: Invalid managed/unmanaged type combination (Arrays can only be marshaled as LPArray, ByValArray, or SafeArray).

when using Cocoon’s refine function and Yellow’s smooth function. I found this post at the old grasshopper forum and, following @DanielPiker 's advice, I updated my .NET framework and made sure plankton was up to date and operational. None of this worked. Does anyone have any suggestions?

I’m running Rhino 5 on Windows 7. I do have Rhino 6 installed but am using 5 for the moment because my computer is garbage.

Hello, I have same issue but i find a solution: put these three file in your GH component folder.

Daniel is right , it is definitely an issue about the Plankton, the reason why i met this error is I have replaced my Plankton(the default one ) with a Plankton(the Meshedit 2000 plugin, downloaded from Food4rhino).

In these three file, The Plankton(default of Rhino 6)
The Plankton.dll and PlanktonGh.dll(from Meshedit 2000)

Plankton issue fix.zip (42.4 KB)

Hope be helpful!