Error calling GET

I’m getting a 500 error, rather than a 404.

While trying to retrieve events, Google returned an error:
Error calling GET https://www.googleapis.com/calendar/v3/calendars/ankenyunited%40gmail.com/events?singleEvents=true&maxResults=2500&timeZone=America%2FChicago&timeMin=2015-12-26T00%3A00%3A00-06%3A00&timeMax=2018-01-24T23%3A59%3A59-06%3A00&key=AIzaSyD7U49C6UDI_j147rNQDeRbV2e568R9ahA: (500) Backend Error

While if I just cut and paste the URL, I seem to get the calendar code:

{
“kind”: “calendar#events”,
“etag”: “\”1453740250156000\””,
“summary”: “[email protected]”,
“updated”: “2016-01-25T16:44:10.156Z”,
“timeZone”: “America/Chicago”,
“accessRole”: “reader”,
“defaultReminders”: [],
“nextSyncToken”: “COCX07m0xcoCEAAYAQ==”,
“items”: [
{
“kind”: “calendar#event”,
“etag”: “\”2725722097132000\””,
“id”: “fdsl0ltla1lom12r4da2aibmrs_20151227T163000Z”,
“status”: “confirmed”,
“htmlLink”: “https://calendar.google.com/calendar/event?eid=ZmRzbDBsdGxhMWxvbTEycjRkYTJhaWJtcnNfMjAxNTEyMjdUMTYzMDAwWiBhbmtlbnl1bml0ZWRAbQ&ctz=America/Chicago”,
“created”: “2013-03-09T20:23:57.000Z”,
“updated”: “2013-03-09T20:30:48.566Z”,
“summary”: “Worship”,
“description”: “Worship is our expression of love for God and love for our neighbors.\nWe worship every week in celebration of Christ’s new life!”,
“location”: “Sanctuary”,
“creator”: {
“email”: “[email protected]”,
“displayName”: “Ankeny UCC”,
“self”: true
},

(etc)

### WordPress Installation ###

Site Name: Ankeny UCC
Home URL: http://www.ankenyucc.org
Site URL: http://www.ankenyucc.org
Version: 4.4.1
Locale: en_US
Timezone: America/Chicago
Multisite: No
Permalinks: /%year%/%monthnum%/%day%/%postname%/
WP Memory Limit: 40 MB
WP Debug Mode: No
Script Debug: No

### Active Theme ###

Theme: Church – 0.7.5
Child Theme: Yes
Parent Theme: Omega – 1.2.8

### Active Plugins ###

Rotating Tweets (Twitter widget & shortcode): 1.8.2
Ultimate Tag Cloud Widget: 2.7.2
Simple Calendar: 3.0.12
Sermon Manager for WordPress: 1.9.5
Wordfence Security: 6.0.23
Cimy Header Image Rotator: 6.1.1
Image Rotator Widget: 1.0.7
iframe: 4.2
Bad Behavior: 2.2.18
Role Scoper: 1.3.67
Role Scoper Migration Advisor: 1.0

### Server Environment ###

Web Server: Apache
PHP Version: 5.6.10
MySQL Version: 5.6.25-log
Server Timezone: UTC
Display Errors: Yes
Safe Mode: No
Memory Limit: 256M
Upload Max Filesize: 64M
Post Max Size: 65M
Max Execution Time: 30
Max Input Vars: 1000
fsockopen: Yes
cURL: Yes
SOAP: Yes
SUHOSIN: No
WP Remote POST: Yes
WP Remote GET: Yes

### Client Information ###

IP Address: 173.236.184.169
Browser: Safari 9.0.2 (Apple)

Thanks for the reply, Nick.

And sorry for piggybacking a different error into this thread. My web forum etiquette has apparently deteriorated over the past few years.

In my case, anyway, I set up the calendar last year and did the API key at the same time. It was working fine until recently (though I missed the exact moment that it broke). The first thing I did was to go through those instructions again and double-check the API key against the dev console and make sure that the calendar was still public. At that point, I noticed that the dev console was reporting server errors.

This morning, on my first visit to the calendar page in my wordpress console, I had the same URL and error message, but when I did a page update (no actual changes), the error message went away (but previewing the changes still showed no calendar), and the google dev console was now showing 400 errors rather than 500. Based on the way the error case changed, I’ve now gone and set up simple calendar on a different site of mine with the same google calendar settings, and it seems to work fine, so there must be some sort of plugin or theme conflict.