Hi, I'm reading up on the tutorial of spice simulation and I'm at the part where it is explained how to use an external LTSpice model. I try to repeat the steps in the tutorial for a TL072 op amp. [https://oshwlab.com/Zoldar71/create-spice-model-of-tl072](https://oshwlab.com/Zoldar71/create-spice-model-of-tl072)<br> <br> When running the simulation I get the following error 'The circuit has components without simulation model: dx'. I pasted the AD817 spice model text from the tutorial example in the schema and changed the op amp symbol name to AD817. Now the simulation runs fine. I can see that the TL072 subckt uses a dx model, but the AD817 subckt also uses a dx model. What am I overlooking? Cheers, Martin