Version mismatch 409

I am trying to update a content entry, but I am always receiving a version mismatch 409 error even though the header (X-Contentful-Version) is being correctly set with the correct version number (12). The current entry version is 11.

I’ve installed “contentful-management” through npm (@5.6.0). I’ve tried it before with 5.7.0 to no avail. Here’s the response:

CONSOLE ERROR VersionMismatch: {
"status": 409,
"statusText": "Conflict",
"message": "",
"details": {},
"request": {
"url": "<spaceid>/environments/master/entries/1ExTmKaQet96QwtEfO76F3",
"headers": {
"Accept": "application/json, text/plain, */*",
"Content-Type": "application/",
"X-Contentful-User-Agent": "sdk contentful-management.js/5.2.1;",
"Authorization": "Bearer ...5152b",
"X-Contentful-Version": 12

"method": "put",
"payloadData": "{\"fields\":{\"id\":{\"en-US\":1},\"movietitle\":{\"en-US\":\"API Panther\"}}}"
"requestId": "12ba512952d9442ddb458a7d2b81dddf"

My code looks like this:

                .then((space) => space.getEnvironment('master'))
                .then((environment) => environment.getEntry('1ExTmKaQet96QwtEfO76F3'))
                .then((entry) => {                  
                    entry.fields.movietitle['en-US'] = 'API Panther';
                    return entry.update()
                .then((entry) => console.log(`Entry ${} updated.`))

I’ve just tried to do the same with the Insomnia REST client. My PUT request looks like this:<spaceid>/environments/master/entries/<contentId>?access_token=<accesstoken>

And my JSON payload:

   "fields": {
     "movietitle": {
       "en-US": "changed"

But I am receiving also a Version Mismatch:

"sys": {
    "type": "Error",
    "id": "VersionMismatch"

I’ve took the syntax for the request from the documentation .

As additional information: I am using a Personal Access Token for authentification.

You need to specify the current version in the X-Contentful-Version header meaning version 11, not 12. See this for more details.