unity2018.3 not working with the ecs package ?

unity2018.3 not working with the ecs package ?
i got error when i use the package manager to import.

 

Which sub version of 2018.3?
It works for me in .0b1

What error you have?

 

All works fine. Try to clean package cache.

 

clean the cache ??

 

As I say - clean package cache.

 

how to do that. i try to remove and install again. but not working.

 

Remove entities package from PackageCache folder, or select entities package in Project window in Packages section and call reimport

 

not work.....
i delete all...reimport..reimport all..still error..

 

You doing that with closed Unity I hope?

 

.....i have try it first...

i use the unity hub to install the 2018.3.0 verison..

 

oh...i know why..

cant create the project using 2D. sorry.