I have FastCube 2.10.6 all pro. I have never used it yet. I don't know if it will go under D11. I can't find any information.
I feel like you canceled it.
Can you give me some basic information?
Fastcube is not a product from tmssoftware.com
I figured it out again 
I apologise
FastCube works pretty well with 11.1 Alexandria. However, I'm using 2021.1 version and I doubt that your obsolete version is supported. I think the upgrade of FC will be necessary.
K.
I'm sorry but FastCube is not a TMS product.