Since updating to the newest version of ACF (5.7.5) I can not use the post relation field anymore. When I try to select a post in the selectbox I get the following JS error:
acf-input.js?ver=5.7.5:11402 Uncaught TypeError: Cannot read property ‘id’ of undefined
Someone of the ACF team? This is quite a big bug for me. I can not use the newest version of the plugin in combination with the post object field because of this.
I have the same issue, this is a pretty big bug imo and should be prioritized.
The bug is introduced in v 5.7.0, going back to 5.6.9 solves it for the moment.
I found out that this has something to do with another version of Select2 thats been loaded by a plugin or whatever.
Unloading the other version of select2 fixed this for me.
+1
Facing this issue since updating to v5.7.0, had to downgrade to v5.6.10.
@jasperrooduijn
Can you please tell me more about how you fixed it?
My problem was dat two versions of the Select2 plugin was loaded. The ACF update loaded a newer version than i was loaded myself. For me the trick was to unload the ACF version i was loading my self. Please check the sourcecode of your backend page to see if multiple versions of Select2 are loaded.