Can you please give us more information about the issue so that we can reproduce it? What part are you trying to import and for what design tool and what version?
when i want to place a microcontroller in schematic of altium designer
(version17.0.8 build518)this error is shown :External exception EEDFADE at 749D18A2.
KERNELBASE.dll, Base Address: 748C0000.
Does that only happen with the same part or it happens also to other parts? It seems like this is a bug with your current version of Altium. Can you please update your Altium into the latest version and try again? I've read something that on version 17.0.9, they have fixed the kernelbase.dll error. So i think updating it with that version or later should fix it.
Let me know if it worked on your end.