TypeError: Cannot read property 'toString' of undefined, map not loading

Question

I have read other similar questions here, but I am not a developer, so I need an answer for beginners (or real dummies) to try and fix my little website.

I am getting this error, which makes my directory site not load the listings on the map (thus rendering the site unfunctional):

JQMIGRATE: Migrate is installed, version 1.4.1
map-template.js?ver=1.0.0:669 Uncaught TypeError: Cannot read property 'toString' of undefined
    at Object.<anonymous> (map-template.js?ver=1.0.0:669)
    at Function.each (jquery.js?ver=1.12.4-wp:2)
    at HTMLSelectElement.<anonymous> (map-template.js?ver=1.0.0:668)
    at Function.each (jquery.js?ver=1.12.4-wp:2)
    at Object.apply_meta_filter (map-template.js?ver=1.0.0:660)
    at Object.filter (map-template.js?ver=1.0.0:556)
    at Object.success (map-template.js?ver=1.0.0:195)
    at i (jquery.js?ver=1.12.4-wp:2)
    at Object.fireWith [as resolveWith] (jquery.js?ver=1.12.4-wp:2)
    at x (jquery.js?ver=1.12.4-wp:4)
(anonymous) @ map-template.js?ver=1.0.0:669
each @ jquery.js?ver=1.12.4-wp:2
(anonymous) @ map-template.js?ver=1.0.0:668
each @ jquery.js?ver=1.12.4-wp:2
apply_meta_filter @ map-template.js?ver=1.0.0:660
filter @ map-template.js?ver=1.0.0:556
(anonymous) @ map-template.js?ver=1.0.0:195
i @ jquery.js?ver=1.12.4-wp:2
fireWith @ jquery.js?ver=1.12.4-wp:2
x @ jquery.js?ver=1.12.4-wp:4
c @ jquery.js?ver=1.12.4-wp:4
XMLHttpRequest.send (async)
send @ jquery.js?ver=1.12.4-wp:4
ajax @ jquery.js?ver=1.12.4-wp:4
n.<computed> @ jquery.js?ver=1.12.4-wp:4
getJSON @ jquery.js?ver=1.12.4-wp:4
init @ map-template.js?ver=1.0.0:182
(anonymous) @ map-template.js?ver=1.0.0:2029
(anonymous) @ map-template.js?ver=1.0.0:2282

Can I fix this by myself?

Thank you so much for any help, kind regards, mira

Answer 1

It's hard to understand a problem without some detailed context. But, what I can see, that you are trying to show some list, where some list items are not defined ( undefined ) or have undefined fields. So these undefined values cannot be converted into strings ( toString() ).

I could be wrong, but what I can suggest is to check presence of all items to show and their fields.