We have an old version of MML running here and we started to see the following error:

We are still unaware of the root cause, whether something was modified inside of our MML setup or something from our control system. The exact error line is here. As the issue is very frequent but irreproducible, I have added a couple of fprintf statement just to see what is happening, it seems at some point the function getramprate returns an empty matrix RampRate (size 0 by 0). What's more weird is that the issue sometimes happens within minutes and sometimes happens after hours. Any help is really appreciated.