As I elaborated, if the plugin ACF stores that field in a non-default WordPress Database table (which HAS to be the postmeta or usermeta table for fields) then CRED can not access it.
There is no way for us to solve this.
Please acknowledge that radios fields, select fields, checkboxes fields, date fields, etc, have specific formats in different plugins.
So anything that is NOT a string or a number will probably be broken after bringing those fields under Types or CRED Control.
This is not Toolset's fault.
It's also not ACF's or WordPress's fault. It's how this works. It's a mix of possibilities in PHP and WordPress that produces these limitations.
To confirm this is the problem, I would suggest you send me a sites snapshot if possible.
We usually recommend the free Plugin "Duplicator" for this porpoise.
If you already know how Duplicator works
(http://wordpress.org/plugins/duplicator/),
please skip the following steps and just send me the installer file and the zipped package you downloaded.
★ Duplicator Instructions
hidden link
Send me both files (you probably want to use DropBox, Google Drive, or similar services, as the snapshot file will be quite big)
❌ IMPORTANT ❌
Remember to create or keep an admin account for me before creating the snapshot, or I won't be able to log in. You may delete the new admin account once the snapshot has been built.
I will enable your next answer as private so you can provide to me the information securely.
Then, I will analyse the Field and the Database and tell you if above is true or not.
Please add an exact description of the Field's name, where I can edit it and where you use it.
With CRED, Views and Types you can build nice galleries.
As an example, you can use Custom Post Types and add your images there, and then use the Views pagination to create a Slider.
https://toolset.com/documentation/user-guides/creating-sliders-with-types-and-views/
Or you can use the FlexSlider Module to create an even nicer Slider / Gallery.
After you install the Module Manager you would see that in the available native Modules:
https://toolset.com/documentation/user-guides/using-toolset-module-manager/