I installed Mac OS Mojave on a new partition for a clean system. As I tried to merge the APFS container of the old Mac OS with the new APFS container with mojave (following the top comment of this How can I merge primary APFS partition with other empty APFS partition?) I encountered the following problem:
Although my SSD has 500GB storage the accessable storage is only 200GB big. When I try to resize any of the two containers with the command
diskutil apfs resizeContainer disk0s2 150g I get the following error.
Using the disk utility app from recovery mode (pressing Cmd + R at startup) yields the same result.
Im out of ideas how to fix this..