Solution
- Close ConCrete.
- Go to C:\Users\*Your_UserName*\AppData\Local\VirtualStore\Program Files (x86)\BuildSoft\ConCrete\. Note that the folder ‘AppData’ is a hidden folder.
- Open CONCINI.TXT.
- Set
hollowcore=1
instead ofhollowcore=0
or delete the linehollowcore=0
. - Save changes and restart ConCrete.