Get some help! :gun:

Hanging initialization - Stiff models

In the event your simulation seems to hang for what seems forever on initialization, check the simulation progress by clicking on the simulation icon in your taskbar.

/images/troubleshooting/taskbar.png)

If you see the message below it means your simulation is either complex (stiff systems do happen) or there are issues with how you have put together your model (e.g., poor initialization conditions or models inappropriately connected)

/images/troubleshooting/stiffmodel.png

Possible Solution

---

1. Change from whatever solver you are using (e.g., DASSL) to a solver meant for handling stiff systems (e.g., ESDIRK45a). Cross your fingers :crossed_swords: and re-simulate.
2. If changing your solver didn't work, take a good hard look at your initial conditions and make sure they are not too wonky.
3. If initial conditions didn't work, try revamping how your model is put together -- of course first check to make sure you have good modeling practices (i.e., no volumes connected to volumes).
4. If that doesn't work that I don't really know what to tell you... Time to start over or simplify your model :frowning2:

Very Large Models Failing Early On

There is a limitation on how much memory may be used in certain ways - 32 vs 64 bit. This can cause large Modelica models to mysteriously fail.

Possible Solution

---

In the command window, ensure you are compiling with 64-bit. This increases the permitted memory usage and has worked in some cases.

Advanced.CompileWith64 = 2