Error on PDF Upload

I am receiving an error when trying to upload PDF’s. After pressing upload the loading animation just hangs. Error from the console:

Uncaught TypeError: g.data.indexOf is not a function
at HTMLDocument.<anonymous> (functions-admin.min.js?ver=1.6.5:1)
at HTMLDocument.dispatch (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,underscore,backbone,wp-util,wp-backbone,media-m&load[]=odels,moxiejs,plupload,wp-plupload,jquery-ui-sortable&ver=4.9.8:3)
at HTMLDocument.r.handle (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,underscore,backbone,wp-util,wp-backbone,media-m&load[]=odels,moxiejs,plupload,wp-plupload,jquery-ui-sortable&ver=4.9.8:3)
at Object.trigger (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,underscore,backbone,wp-util,wp-backbone,media-m&load[]=odels,moxiejs,plupload,wp-plupload,jquery-ui-sortable&ver=4.9.8:3)
at Object.a.event.trigger (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,underscore,backbone,wp-util,wp-backbone,media-m&load[]=odels,moxiejs,plupload,wp-plupload,jquery-ui-sortable&ver=4.9.8:9)
at y (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,underscore,backbone,wp-util,wp-backbone,media-m&load[]=odels,moxiejs,plupload,wp-plupload,jquery-ui-sortable&ver=4.9.8:4)
at XMLHttpRequest.c (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,underscore,backbone,wp-util,wp-backbone,media-m&load[]=odels,moxiejs,plupload,wp-plupload,jquery-ui-sortable&ver=4.9.8:4)

When I view the media library, I can see that the PDF get’s uploaded.

I have tested this in both Firefox and Chrome.