InvalidArgumentException: Malformed UTF-8 characters, possibly incorrectly encoded in Symfony\Component\HttpFoundation\JsonResponse->setData

Hi team,

My application is on different languages and error is coming on Fr language page load time.Can you please help me to resolved this issue and identified what i can do so my issue will get fix soon.

1.) Below is application error log message (watchdog report error log):

Type php
Date Tuesday, December 10, 2019 - 10:52
User kpurohit
Location https://domain.com/ch/fr/api/v1/events?_format=json
Referrer https://domain.com/ch/fr/events
Message InvalidArgumentException: Malformed UTF-8 characters, possibly incorrectly encoded in Symfony\Component\HttpFoundation\JsonResponse->setData() (line 168 of /var/www/deployments/vendor/symfony/http-foundation/JsonResponse.php).
Severity Error

Browser Ajax API call response on initial page load:

Request URL: https://domain.com/ch/fr/api/v1/events?_format=json
Request Method: GET
Status Code: 500 500 Service unavailable (with message)
Remote Address: 52.73.51.196:443
Referrer Policy: no-referrer-when-downgrade
Cache-Control: must-revalidate, no-cache, private
Connection: keep-alive
Content-language: fr
Content-Length: 86
Content-Type: text/plain; charset=UTF-8
Date: Tue, 10 Dec 2019 09:44:12 GMT
Expires: Sun, 19 Nov 1978 05:00:00 GMT
Server: Apache
Vary:
X-Content-Type-Options: nosniff
X-Frame-Options: SameOrigin
X-UA-Compatible: IE=edge
Accept: application/json, text/javascript, */*; q=0.01
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9
Connection: keep-alive
Cookie: _ga=GA1.2.1658418532.1574345227; _hjid=97f08166-0c9a-421f-9c84-906c1acdbf49; LPVID=AwZjNjNzI2MmUzYjIyNTIy; __zlcmid=vQiiBAGlmkNyMY; COMMAND=; __utma=13110440.1658418532.1574345227.1575445959.1575445959.1; __utmc=13110440; __utmz=13110440.1575445959.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); _gid=GA1.2.1351159962.1575901369; PLG=Message=+&PACECOMPANY=370&LOGGEDINLANGUAGECODE=DEU&LOGGEDINLANGUAGEID=10&PACELANGUAGECODE=DEU&LOCALECODE=de&LOCALEID=de-CH&LANGUAGEID=10&COUNTRYCODE=CH&LOGGEDINLOCALECODE=de&L=09-Dec-2019+19%3a39%3a59&SID=&ALLOWORDERENTRY=1&BankAccountDataExists=0; LPSID-32765544=_LIeGjdHQLGWODFa003pfg; SSESSc0fc08df3e12b2fb52840d438a72ee23=RH-y2_zOGjFAiIqDRVZTaGTaKDcM3Uq2z_icrBeH45o; _gat=1; _dc_gtm_UA-46553254-20=1; last_visited_url=https://domain.com/ch/fr/events
Host: domain.com
Referer: https://domain.com/ch/fr/events
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-origin
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36
X-Requested-With: XMLHttpRequest
_format: json