Upgraded to Confluence 6.8.1 and getting 500 server errors

[Gilad David Maayan]

We upgraded a Confluence instance to version 6.8.1 and are getting thousands of 500 server errors, which look like the below. Can you advise what is causing these errors and how to prevent them?

{  "_index":   "_type": "nginx",  "_id": "AWLIoO24uyZAlXugjbtC",  "_score": null,  "_source": {    "request": "/visualweb/s/it_IT/7701/445126ab56584205167f1c035c86df495c7c4192/1.0/_/download/resources/confluence.web.resources:ajs/images/brand-images/programs/atlassian-developer-white.svg",    "agent": "axios/0.17.1",    "role": "ui",    "auth": "-",    "ident": "-",    "type": "nginx",    "rails_timestamp": "2018-04-15T09:26:50.000Z",    "http_host": "cloudinary.com",    "geo": "us",    "request_time": "0.239",    "rails": "false",    "@version": "1",    "cld_version": 414,    "host":     "host_ip":    "x_cld_error": "-",    "input_type": "log",    "verb": "GET",    "bytes_sent": "62346",    "tags": [],    "x_forwarded_for":     "referrer": "-",    "elb_ip": "10.0.2.179",    "@timestamp": "2018-04-15T09:26:51.014Z",    "instance_id":     "request_length": "392",    "response": "500",    "bytes": "61806",    "az":     "httpversion": "1.1",    "region":   },  "fields": {    "@timestamp": [      1523784411014    ],

[KC Integrations]

What the outcome from this, I am now getting hundreds of these error in Confluence 6.15.3

[Edwin Kyalangalilwa]

Hi Gilad,

Please post the error from Confluence logs.

What version did you upgrade from?

[Gilad David Maayan]

Here is the log showing the error:

https://drive.google.com/file/d/19jSLsKk7ygBcQS29T6M-lFtxk4M5HaU6/view?usp=sharing

We upgraded from 6.1.2. Thanks for your help!