Because you did not read : [https://easyeda.com/forum/topic/How-to-ask-for-help-and-get-an-answer-71b17a40d15442349eaecbfae083e46a](https://easyeda.com/forum/topic/How-to-ask-for-help-and-get-an-answer-71b17a40d15442349eaecbfae083e46a) so you are using a schematic symbol for a diode that does not have a simulation model associated with it. If you check your spice netlist you will find that there is no model pulled in for the zener diode. [S](https://easyeda.com/forum/topic/How-to-ask-for-help-and-get-an-answer-71b17a40d15442349eaecbfae083e46a)o as a minimum, please read (3) in (2) in the post above and then post the link to this as a public project. Thanks.

Thanks for your reply. Trust me I spent best part of a day, trying to make some sense out of all this and get things to work. Asking at a forum is usually my last resort. I understand what you are saying and appreciate your reply. But unfortunately it does not easy my frustration and i am still quicker with my soldering iron and half way decent collection of physical components. There has to be something more user friendly out there than this.

Further to what you are saying, why is there no error message or warning when one uses those "dead" components ?

If you go back to the Search libraries tool and look for:  and then place that in your simulation schematic then it will run OK. Note that spice symbols have a small "S" character in them in the Search Libraries tool. Even then, if It's not shown as being in one of the System libraries then it probably will not work. Admittedly, this particular one I only added last night and because of a change in the the way the Tags are recognised this particular part is not found by simply looking in the Spice Discrete library or searching for just BZX84.