- Create a object of UParticleSystemComponent and keep it as a member in c++.
- Assign the value of false to the property of ‘bAutoActivate’.
- Create a Blueprint class based on step1 (select a particle template for the component, after that you will see nothing happened, that’s right)
- Open c++ file for updating, update the property of ‘bAutoActivate’ by using the opposite value.
- If everything work well, you will see the performance of particle in the blueprint viewport, but get nothing.(After I reselect a new particle template, the result is also the same)
Based on the reproduction, the behavior here is the same as what you reported in your other post (The update of c++ is not in sync with blueprint - C++ - Epic Developer Community Forums) . This all falls under the bug mentioned there (Unreal Engine Issues and Bug Tracker (UE-43856)) as a hot reload issue. Thank you for letting us know about this instance as well.