Issue with custom Doctype that remains blank when refresh page

I have a custom Doctype and I have put it in Manufacturing > Setup.
Sometimes, when I access the custom Doctype and refresh the page, the program does not load the page (it remains blank) and I must return and access the custom Doctype again.

In the Web Console, I can see that this behaviour is returning a SyntaxError:

Unable to handle success response       desk.min.js?ver=1538737731.0:1566
SyntaxError: Unexpected token ;         desk.min.js?ver=1538737731.0:1566
    at Object.init_doctype (desk.min.js?ver=1538737731.0:5489)
    at Object.callback (desk.min.js?ver=1538737731.0:5471)
    at Object.callback [as success_callback] (desk.min.js?ver=1538737731.0:1437)
    at _ (desk.min.js?ver=1538737731.0:1461)
    at Object.<anonymous> (desk.min.js?ver=1538737731.0:1562)
    at i (jquery.min.js:2)
    at Object.fireWith [as resolveWith] (jquery.min.js:2)
    at z (jquery.min.js:4)
    at XMLHttpRequest.<anonymous> (jquery.min.js:4)
(anonymous)         @ desk.min.js?ver=1538737731.0:1566
i                   @ jquery.min.js:2
fireWith            @ jquery.min.js:2
z                   @ jquery.min.js:4
(anonymous)         @ jquery.min.js:4 
load (async)
send                @ jquery.min.js:4
ajax                @ jquery.min.js:4 @ desk.min.js?ver=1538737731.0:1548         @ desk.min.js?ver=1538737731.0:1441
with_doctype        @ desk.min.js?ver=1538737731.0:5451
make                @ list.min.js?ver=1538737731.0:1552
show                @ desk.min.js?ver=1538737731.0:9651
show                @ list.min.js?ver=1538737731.0:1573
(anonymous)         @ desk.min.js?ver=1538737731.0:27
frappe.route        @ desk.min.js?ver=1538737731.0:2193
startup             @ desk.min.js?ver=1538737731.0:12206
load_startup        @ desk.min.js?ver=1538737731.0:12175
init                @ desk.min.js?ver=1538737731.0:12171
Class               @ desk.min.js?ver=1538737731.0:37
frappe.start_app    @ desk.min.js?ver=1538737731.0:12155
(anonymous)         @ desk.min.js?ver=1538737731.0:12166
i                   @ jquery.min.js:2
fireWith            @ jquery.min.js:2
ready               @ jquery.min.js:2
J                   @ jquery.min.js:2

What could this be about?