Universal Robots Forum

Unknown error: ValueStack is Full

I am running Polyscope 5.11 on a UR10e.

I get the following error message when running a large (100,000+ lines) URScript:
“Unknown error: ValueStack is Full, capacity = 1048576, needed size = 1048778”.

Has anyone encountered this error or know a solution?


Search the forum for valuestack and you will find other answers to this question. It depends on whether you are trying to run this externally (streaming a program to one of the client interfaces) or running it directly on the controller within Polyscope. Program.urp is going to get compiled into program.script and the .URP version of the program will have more restrictions in size. A pure program.script program (this is what the controller really ‘runs’) could generate this error if you are attempting to use arrays that are too large too.

The other thing worth mentioning is that URcaps will make contributions to the installation file and this will get included in the final compile and affect the size of the final program.script that you run. IF there are URcaps installed that you are not using it might help to uninstall them.

Unfortunately we do not publish any specs on max program size or array size.


If I remember correctly, loading a script file with functions that you want to call later multiple times instead of only once might also lead to this or at least a similar sounding error message.
If you are using script files that only contain procedures that you call later with assignments, you might check if you load the same script several times.

Best regards