For some reason the date picker on one of my pages keeps breaking, When the datepicker stops working, I get an error in the console.log
frontend.js?ver=2.3.6:431 Toolset Forms: Error parsing callback data for `check_post_id`
(anonymous) @ frontend.js?ver=2.3.6:431
i @ jquery.js?ver=1.12.4:2
fireWith @ jquery.js?ver=1.12.4:2
y @ jquery.js?ver=1.12.4:4
c @ jquery.js?ver=1.12.4:4
XMLHttpRequest.send (async)
send @ jquery.js?ver=1.12.4:4
ajax @ jquery.js?ver=1.12.4:4
n.<computed> @ jquery.js?ver=1.12.4:4
initQueue @ frontend.js?ver=2.3.6:425
(anonymous) @ frontend.js?ver=2.3.6:633
setTimeout (async)
(anonymous) @ frontend.js?ver=2.3.6:632
(anonymous) @ frontend.js?ver=2.3.6:712
VM404:1 Uncaught SyntaxError: Unexpected token < in JSON at position 0
at JSON.parse (<anonymous>)
at Function.n.parseJSON (jquery.js?ver=1.12.4:4)
at Function.a.parseJSON (jquery-migrate.min.js?ver=1.4.1:2)
at Object.success (date.js?ver=0.1.2:97)
at i (jquery.js?ver=1.12.4:2)
at Object.fireWith [as resolveWith] (jquery.js?ver=1.12.4:2)
at y (jquery.js?ver=1.12.4:4)
at XMLHttpRequest.c (jquery.js?ver=1.12.4:4)
What's on these pages where this happens? Is it a Form with a datepicker, or a View with datepicker filter controls, or something else?
Does the error happen predictably, inasmuch as it happens every time you visit the same problem page(s)?
Can you check for conflicts, re-testing those same pages?
Disable all non-Toolset plugins and switch theme to twentynineteen then try again. If the issue disappears then it should be possible to determine the source of any conflict by a process of elimination.
Let me know how that goes so I can see how to proceed.