Error when trying to trim borders

[calmingcolor]

I make a lot of my own custom covers and unfortunately since upgrading to 8.1.1 - automatic and manual trimming of cover borders within edit meta data is no longer working. When I click the screen it quickly errors out. Currently running calibre on apple silicon mac OS 15.4. Unsure if it is a me problem or something larger. Thanks for anyone's help in trouble shooting!

Here is the error report I got:

calibre, version 8.1.1
ERROR: Unhandled exception: <b>ZeroDivisionError</b>:division by zero

calibre 8.1.1 embedded-python: True
macOS-15.4-arm64-arm-64bit Darwin ('64bit', '')
('Darwin', '24.4.0', 'Darwin Kernel Version 24.4.0: Wed Mar 12 21:24:54 PDT 2025; root:xnu-11417.101.13~4/RELEASE_ARM64_T6041')
Python 3.11.5
OSX: ('15.4', ('', '', ''), 'arm64')
Interface language: None
EXE path: /Applications/calibre.app/Contents/MacOS/calibre
Successfully initialized third party plugins: Gather KFX-ZIP (from KFX Input) (2, 22, 0) && DeDRM (10, 0, 3) && Package KFX (from KFX Input) (2, 22, 0) && Apple Books covers (0, 2, 0) && BOL_NL (5, 2, 2) && Barnes & Noble (1, 5, 6) && Category Tags (0, 3, 2) && Count Pages (1, 13, 6) && Ebook Translator (2, 4, 0) && EpubCheck (0, 2, 5) && EpubMerge (3, 2, 0) && EpubSplit (3, 10, 0) && Find Duplicates (1, 10, 9) && Goodreads (1, 8, 2) && Goodreads More Tags (1, 2, 1, 2) && Goodreads Sync (1, 16, 11) && Hardcover (0, 2, 2) && Job Spy (1, 0, 239) && KFX metadata reader (from KFX Input) (2, 22, 0) && From KFX (2, 22, 0) && KFX Input (2, 22, 0) && Set KFX metadata (from KFX Output) (2, 14, 0) && KFX Output (2, 14, 0) && KOReader Sync (0, 6, 8) && Kindle Collections (1, 7, 29) && Kindle hi-res covers (0, 5, 1) && Kobo Books (1, 9, 2) && Kobo Metadata (1, 10, 0) && Kobo Utilities (2, 21, 1) && LubimyCzytac (2, 3, 3) && Manage Series (1, 5, 2) && Media File Importer (1, 0, 27) && OverDrive Libby (0, 2, 3) && Quality Check (1, 14, 1) && Reading List (1, 15, 4) && Resize Cover (1, 2, 1) && SmartEject (2, 6, 0)
Traceback (most recent call last):
File "calibre/gui2/dialogs/trim_image.py", line 188, in selection_area_changed
ZeroDivisionError: division by zero

[kovidgoyal]

https://bugs.launchpad.net/calibre/+bug/2105373