image-occlusion-enhanced Crash: Hold CMD + C while 'mask' is selected

Problem description

When attempting to copy the mask size in order to have the same size for all the information I want to mask Anki will crash when I select a mask and hold cmd + c (to copy)

Checklist

Please replace the space inside the brackets with an x if the following items apply:

[x] I've restarted Anki to see if it helps
[ ] I've verified that I use the latest version of the add-on by redownloading it from AnkiWeb
[x] I've verified that I use the latest version of Anki by checking at https://apps.ankiweb.net#download
[ ] I've tried to disable other add-ons to see if there are any interactions present
[ ] My issue disappears when I hold shift while starting Anki.
[x] I've checked if anyone else reported this problem before by looking through the issue reports. I also checked to see if there is a section about known issues in the add-on description, documentation, or README.

Information about your Anki set-up

Please open Anki, go to Help → About, click on "Copy Debug Info", and paste the result between the backticks below (if the button does not appear you are using an older version of Anki 2.1 and will need to update first):

    Anki 2.1.44 (b2b3275f) Python 3.8.6 Qt 5.14.2 PyQt 5.14.2
    Platform: Mac 10.16
    Flags: frz=True ao=True sv=2
    Add-ons, last update check: 2021-05-27 16:22:28
    
    
    ===Add-ons (active)===
    (add-on provided name [Add-on folder, installed at, version, is config changed])
    Add Table ['1237621971', 2020-07-25T14:19, 'None', mod]
    AnkiConnect ['2055492159', 2021-05-09T00:06, 'None', mod]
    Card browser List only one card per note ['797076357', 2020-08-11T06:23, 'None', '']
    Image Occlusion Enhanced for Anki 21 alpha ['1374772155', 2020-04-28T04:21, 'None', '']
    ImageResizer ['1214357311', 2021-04-10T18:15, 'None', '']
    LPCG LyricsPoetry Cloze Generator ['2084557901', 2020-07-12T01:06, 'None', '']
    Life Drain ['715575551', 2021-04-03T08:26, 'None', '']
    Mini Format Pack ['295889520', 2018-07-24T19:45, 'None', '']
    Pop-up Dictionary beta ['153625306', 2019-03-23T18:32, 'None', '']
    Searching PDF Reading  Note-Taking in Add Dialog ['1781298089', 2021-05-16T13:53, 'None', mod]
    Syntax Highlighting FORK night mode fix gui config etc ['1972239816', 2021-03-15T20:54, 'None', mod]
    
    ===IDs of active AnkiWeb add-ons===
    1214357311 1237621971 1374772155 153625306 1781298089 1972239816 2055492159 2084557901 295889520 715575551 797076357
    
    ===Add-ons (inactive)===
    (add-on provided name [Add-on folder, installed at, version, is config changed])
    Export deck to HTML ['1897277426', 2020-09-02T15:52, 'None', '']
    Export in CSV format ['1478130872', 2019-01-21T19:21, 'None', '']
    Improved Quizlet to Anki 21 Importer ['538351043', 2020-11-15T03:16, 'None', '']
    Review Heatmap ['review_heatmap', 2020-04-30T15:23, 'None', '']
    Syntax Highlighting for Code ['1463041493', 2018-10-07T03:31, 'None', mod]