Having same problem and i ended in the same as kcalv said about acf_form_head();
And for what i could see the problem start since this change on the wp core:
https://github.com/WordPress/WordPress/commit/7e7b70cd1ae5772229abb769d0823411112c748b#diff-9c3519f4870fac83dc0dbf18cb6bd4c4
See how it´s added a new “__ = wp.i18n.__;” into the ColorPicker var.
I guess many other changes in core about i18n and how js uses translations are the problem here, sine i saw many other plugins that are having the same not defined “wp”.
For what i see this is a change that affects many other things, all related on how js uses translations, basicly this:
This removes the usage of wp_localize_script() for passing translations to the script and instead adds the translatable strings in the script directly through the use of wp.i18n and its utilities.
Hope this help to find the solution.
