How to solve this problem?

when i use python to built codes,the dynamo happens like this:

now ,i do not know how to handle this problem .
can you help me ? very thanks!

Hi,

You’re using Dynamo in sandbox mode. The sandbox has no access to Revit resources. Try launching Dynamo from inside Revit instead.

oh,thanks,i will try .i use dynamo in sandbox mode indeed.
thanks a lot.!