I can’t edit gallery after First time only first photo is showing up

If i want to make a change to a created gallery only the first photo is showing up and i cannot make changes. I allready send yesterday a support request, but no response.

When i press F12:

JQMIGRATE: Migrate is installed, version 1.4.1
jquery.minicolors.min.js?ver=1.1.25:976 pre events
photoblocks.admin.js?ver=1.1.25:16 loading gallery
photoblocks.admin.js?ver=1.1.25:16 gallery loaded
packery.pkgd.js?ver=1.1.25:311 Mixed Content: The page at ‘https://chantalheijnen.com/wp-admin/admin.php?page=photoblocks-edit&id=14’ was loaded over HTTPS, but requested an insecure image ‘https://chantalheijnen.com/wp-content/uploads/2018/11/Midterms_California-Zephyr_01-1024×683.jpg’. This content should also be served over HTTPS.
getSize @ packery.pkgd.js?ver=1.1.25:311
photoblocks.grid.js?ver=1.1.25:321 Uncaught TypeError: Cannot read property ‘col’ of undefined
at _pendBlock (photoblocks.grid.js?ver=1.1.25:321)
at appendBlock (photoblocks.grid.js?ver=1.1.25:360)
at photoblocks.grid.js?ver=1.1.25:741
at Function.each (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,underscore,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jquery-ui-cor&load[]=e,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=4.9.8:2)
at Object.setBlocks (photoblocks.grid.js?ver=1.1.25:738)
at Object.success (photoblocks.admin.js?ver=1.1.25:524)
at i (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,underscore,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jquery-ui-cor&load[]=e,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=4.9.8:2)
at Object.fireWith [as resolveWith] (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,underscore,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jquery-ui-cor&load[]=e,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=4.9.8:2)
at y (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,underscore,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jquery-ui-cor&load[]=e,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=4.9.8:4)

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