Without system and version info nobody can tell you much. Presumably you may have a permissions issue on the packs or a compatibility problem, because they work different from the commercial packs.
Are you still facing this problem with Element 3D? If not, let us know how you solved it. If so, please let us know so we can assist you further.
I am also having this same problem now in August I have a video for it on whats going on if you want to see it ill drop the link . It actually just stopped working the other night. When you click on Scene Setup it responds as if its opening, but no window loads but locks up After Effects completely on a brand new composition/Project. I've tried turning off both monitors as I am running 2 4K and still nothing. when you check processes and programs opened you cannot find element 3D anywhere. . I know this is a problem for videocopilot and I should be posting on their forum but I cannot even seem to be able to get past registration LOL.
Build: Element x64 2.2.2 (2155.hotfix)
OS: Microsoft Windows 10 Home 64-bit 10.0.14393
CPU: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
GPU Vendor: NVIDIA Corporation
GPU: GeForce GTX 1070/PCIe/SSE2
GPU Driver: 184.108.40.20676
GPU RAM: 8192MB
GPU Code: 0
CL0: GeForce GTX 1070 (50.0%) (GL Interop)
CL1: GeForce GTX 1070 (50.0%)
First thing I would do would be to update your GPU drivers and restart your computer.
Yeah I solved the problem not a driver issue wasn't a restart computer issue. drivers up to date and did restart multiple times. So it was my mistake and I tested it a 3rd time and now I am not trying it again. The element 3D crash fix delete the cache well I deleted all the files and it kept queuing me to add my element 3D license again. This happened twice in one month. for someone reason the screen to add license didn't pop up this particular moment and had to mess with it a few times before I got it to work.