Another Allplan user replied in the German forum ( https://campus.allplan.com/de/forum/themen/topic/topics/cad-visual-scripting-1/allplan-2021-0-3-reagiert-bei-vs-nicht-mehr.html ) and suspected that I have a circular reference in my script, where the output of a node is connected to the input of a node further to the left and thus a kind of feedback occurs.

I had several circular references in my script, which I eliminated by rearranging the nodes (see picture 1). This actually fixed the problem for some nodes(although sometimes it takes a bit longer than usual), but not for all: In picture 2 and 3 you see some simple lines. In the first case, I could easily connect them with eachother, but in picture 3 I tried to connect them with the existing line on the right and it didn`t work again. Allplan 2021 stopped working.

But what I am still wondering is why this problem already occurs when arranging the nodes on the VS surface and not after running the script? The Allplan user suspects that the arrangement is checked when the connection is established and is just not recognised due to identical UUID's, which is why such an endless loop triggers this checking routine.

It is also strange why this only occurs in Allplan 2021-0-3 and not in Allplan 2020. Do you know if there`s been a change in the checking routine in version 2021?

Regards,

Marco