The same codes return different results

I am curious about the fact that the first time I run the codes, it returns what I want(namely, a 88 list of surfaces), but the second time it returns 28 list of surfaces, which is shown below.
What’s more, sometimes it returns a error, but I am sure there is no problem. So I guess maybe there are some problem about memory. Dynamo may remember values of some variables, which should be Null value before the codes run.
Is my guess possible? And how to slove this problem?
I am new to Dynamo and not good at English. Any help is appreciated. Thanks very much.

PS: a short while ago I got the correct return. The result is shown below. I just close Dynamo and reopen it. But I still want to know the reason because this situation has happened many times and deeply troubled me. Could anyone give some advice? Thank you.

@1549041984 Assuming you’re using an older version of Dynamo, I’d suggest trying one of the more recent versions / builds.

I am using version 1.1. Is there more recent versions? And where to find them?
And I am curious how you can know my version?

The daily builds are available at http://dynamobuilds.com/

Wasn’t sure, just suspected as I used to have similar issues with some earlier builds (not 1.1, though)

If the problem persists you might want to report it at https://github.com/DynamoDS/Dynamo/issues