Steven Zahm@ Harald
RE: Seems like all my troubles are unique…
With many thousand in sales and far many more in total installations over nearly a decade, yes, most issues tend to be more unique if they are not straight up conflicts. When more than a handful have experience a similar issue I code in workarounds. Here’s one example to which you can relate:
Over the course of the past several years a few dozen or so users Form would not send when the submit button was clicked. And its Add buttons would just cause the form to jump to the top of the page. For all those past users who experienced this, I simply provided a code snippet that forced the javascript for Form to be loaded vs. doing it the right way. For some reason the right way, for them, was not working. A few days before you posted about this issue another had the same issue. The solution for that user was to check if a specific core WP script was registered and if it was not, register it. Something in that users setup was unregistering a core WP script, something that should not be done because of this exact reason. Other plugins may depend on it. If you recall that solution had not worked for you. When debugging your issue I notice the text editor for the bio/notes field was working which meant other core WP scripts were being loaded into the page footer like they should be, but the javascript for Form was not. So I researched how WP was ensuring that they were and mimicked that process in Form and applied that as a hot patch to your site. One should not have to jump thru those hoops as WP provides a specific method for plugin devs to use to output plugin’s javascript. Now that I have these two workarounds in code, I expect this issue to be even more rare.
I am supporting another user this very moment where the Customizer is not loaded for them, but when I log in, it works for me using the exact same login as he is. Would you not also consider that unique?
Any way, back on to sorting out why the Customizer is not loading for you…