If you see "No model specified," the library you downloaded may only be a graphical symbol without a simulation model ( .MDF file). Ensure your download includes the SPICE model .
: This site is a primary source for specialized Proteus libraries. You can search their library collection for the SG3524 model. sg3524 proteus library download link
https://github.com/embeddedlab786/Proteus_Library/tree/main/SG3524 If you see "No model specified," the library