I have created a complicate generic element by dynamo but afterward, the generic element cant get the Geometry (Which i want is its Solid). Anyone have experience this issue before? could you help me
Why not just work with the solid you fed into the FamilyInstance.ByGeometry node?
Because its the sequence so solving problem, i need this Generic Element for first. then another script will get all Generic element in view to continue the work
Ok. The May ha e to do with the SAT (I think that’s it) import method used by that node. You may have to rebuild the solids by a Solid.ByJoinedFaces node.
Sorry for late response, i tried export SAT and Import later but its turn out the same element (which not a solid). Now i solve my problems by another way. but i still curious about how Generic node work. I absolute put a solid into Generic Node, but its came out in-correct geometry in Revit.??? what should i do in other case?
I heard some say its only work with python/C# script. isnt it?
Its kind of wierd, i used solid.Volumne to get the volumne of before generate Generic Element. The compared with default volumne of generic model created you can see in attached picture.
This is my file (revit 2018 + dynamo 2.0.2xx) in case you want to test yourself.
https://drive.google.com/drive/u/1/folders/1osUeicSMt8nMbhoFU04Ze8j9rgx9QHxb
What was incorrect?
I won’t be at a CPU until late next week, but I’ll try to remember to look this over. 9/10 times it is because your solid has a face with an inverted normal (points into the solid instead of out of). You can test this by finding a point and normal at UV parameter 0.5, 0.5; and using a Geometry.Translate By Direction Distance method to move the point by a small amount - say 1/10 of your shortest edge; then ask if the translated points intersect your original solid - if so those faces need to be reversed. If not you’re up against something else.
I still dont figure out what is the problem, it would be nice if you could take a look at the file in link google driver above. I also attach the illustrate pic what i want to build. Hope to recive your response,
Thank you and good day 
Still on vacation. 
Looked into this today - bigger issue at play with the geometry you’re feeding into the FamilyInstance.ByGeometry node.
This example certainly works without issue in the way you’re looking to use it, albeit much simpler in form.
I suggest looking into a simplier version of the geometry - perhaps adding each cap individually as a solid instead of a mass of solids - so that the error causing element can be identified. I took a stab at this but the geometry is a bit more complex then readily solves with OOTB stuff, and I don’t know of a package which groups intersecting geometry as you’ll need to in order to prevent duplicate volumes from being added. BiMorph may contain the type of code needed, however it doesn’t run on sandbox so I’m unable to test at the moment. If I get some time to build some code that groups common stuff by intersections via design script, no promises though.