I put this question by mistake on the Rocket forum first. So here’s it again.
I was trying to change the mesh of a static mesh actor I put up in a level, along with its material. While the material does change dynamically, whenever I recompile the level blueprints, the Static Mesh component loses it default mesh value and does not accept anything again.
Is this a bug or am I doing something wrong? I want this in Level blueprints only, because then I have to set it up with Matinee actors, which don’t work with the other blueprint actors.
Please post your BP graph 
Rama
I am trying to make a tutorial here so I’ll try to not give spoilers 
But here you go.
The whole thing is, that I have put 3 different Static Mesh actors in the scene, with a Matinee and Material of each of them. I am using a Switch mode too, on each switch there is 1 “Set Static Mesh” node. And after each of these is a Set Material and Matinee node. This is supposed to set a different static mesh on each SM Actor, with a different Material as well as a Matinee path on each switch. But the whole thing goes for a toss in the beginning itself, when the required SM Actor is not set to a chosen SM taken from the Content Browser. 
Also, the “Rocket 01” node that you see, I selected a SM Actor in the level, came to BP graph, did a right click and added a reference for the Actor, which gave me this node. The Target node, sort of typecasts the SM Actor to a SM component.
#Mobility = Moveable
Static Mesh’s wont change their mesh unless they are set to Mobility::Moveable

I encountered this same issue when trying to set Static Meshes via C++
I do believe it is expected behavior, because the shadow shape and lighting has to change if you change a static mesh, and Mobility::Moveable uses all the dynamic lighting fabulousness of UE4 
Rama
I have set it to that too, since the start. If its not Moveable it won’t even get accepted in Matinee. But it still bugs me 
I could however do with BluePrint actors, but then they don’t accept Matinee sequences and all basic animation is done only with Timeline :\
#Solution
Delete all of your blueprint related to setting static mesh (like the 4 nodes in your pic)
it will automatically add a reference to your selected mesh actor
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pick the mesh using that grid icon/array icon
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Then activate this node sequence (two nodes) on key press or level start or whatever
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Set the Static mesh actor you chose in level and press F4
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Set the Mobility to Moveable
Done!
#Summary
Send the Actor into Set Static Mesh instead of the static mesh component
Rama
PS: I just tested this as working!
Wow! ok!
Will try this…and add your acknowledgement. 
On the other hand, while being desperate to make this work, I even came up with a solution to link the Blueprint actor to Matinee 
Will add both techniques in the tutorial.
Next question. A little personal, if I may ask: Where are you from, and where do you work? 
Next question. A little personal, if I may ask: Where are you from, and where do you work? 
I run my own healing business at www.evernewjoy.com
So I work from home 
I am not sure exactly what “where are you from?” is asking,
so I’ll say I am from the Universe

Rama
Aah!! Wow! a versatile man! 
After you said Universe…I can’t ask you anything else
Peace out!
And thanks for sorting the doubt!