Description of problem:
When using automatic partitioning, trying to modify change partition sizes fails. It also seems to happen when doing custom partitioning when modifying sizes of a partition designed in UI, fails.

I have an Existing Windows 7 partition on the laptop, with a 100MB reserved partition required by Windows.

Version-Release number of selected component (if applicable):
anaconda 21.48.10-1

How reproducible:
I managed to get it to work once, but aborted to get bug logged.I can reproduce this every time pretty much.

Steps to Reproduce:
1. Unsure if you need Windows partitions created or not 
2. Either wipe existing Linux partition or have none prior 
3. Choose Automatic partition, then try to resize (shrink) the size chosen, fails on some partitions such as /home

Actual results:
Error from Anaconda but no exception or if you attempt to proceed anyway, Anaconda fails and throws full exception dump.

Expected results:
Able to change the automatic partition parameters in UI manually.

Additional info:

I've attached the logs