I was pumped to see 6.4.1 shipping with the option for custom tabs and custom icon groups in the Icon Picker field.
I was able to successfully get it to work on an Options page and in a custom taxonomy. However, custom tabs in the icon picker don’t load for me when assigning them to a block. The icon area just stays empty.
Has anybody had any luck with custom icons for the icon picker in blocks?
I just came across the same issue. The tab appears, but is empty. I have not found any solution.
I was in (a little slow-going) contact with the support and they confirmed this as a bug that will be fixed in a future release. There’s no quick fix for this it seems.
