Did you see that another user has already raised out the same problem? It’s not only my problem.
On your plugin page admin.php?page=mycred-hooks, chrome inspector as follows:
load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:9 JQMIGRATE: Migrate is installed, version 1.4.1
load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:3 The specified value “!” does not conform to the required format. The format is “#rrggbb” where rr, gg, bb are two-digit hexadecimal numbers.
ja @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:3
n.parseHTML @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:4
a.fn.init @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:9
n @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:2
(anonymous) @ spectrum.js?ver=4.9.10:3
(anonymous) @ spectrum.js?ver=4.9.10:3
(anonymous) @ spectrum.js?ver=4.9.10:80
admin.php?page=mycred-hooks:494 GET https://www./wp-content/plugins/product-preview-for-woocommerce/images/ad_white_on_orange.png 404
load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:4 POST https://www./wp-admin/admin-ajax.php 403
send @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:4
ajax @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:4
(anonymous) @ admin.php?page=mycred-hooks:3553
i @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:2
fireWith @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:2
ready @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:2
K @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:2
load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:4 POST https://www./wp-admin/admin-ajax.php 403
send @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:4
ajax @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:4
(anonymous) @ ai-admin.js?ver=2.4.8:17
i @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:2
fireWith @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:2
ready @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:2
K @ load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-draggable,jquery-ui-sortable,moxiejs,&load[]=plupload&ver=4.9.10:2
A bad HTTP response code (404) was received when fetching the script.