Steps to reproduce:
1) Boot with latest install image
2) Select custom partitioning
3) Create custom partitions
4) click done/back
5) Go back to the partitioning screen and click the plus sign
The window is not created. If you hit escape you can hit back. However, this happens every time after the first time you visit the custom partitioning screen.
Reproduced. The window seems like stuck. +1 blocker
I have learned that sometimes you need to visit the screen more than twice, sometimes twice is enough. It might be relevant to what exactly you click, or some race condition. Attaching logs from one such attempt.
Created attachment 673849 [details]
Created attachment 673850 [details]
Created attachment 673851 [details]
Created attachment 673852 [details]
Created attachment 673853 [details]
Created attachment 673854 [details]
This is the same as bug 875291. And I am extremely pessimistic on the chances for figuring out a fix for this.
*** This bug has been marked as a duplicate of bug 875291 ***