telegraf: Why bot suddenly crashed?

This code was working properly one month ago but since last night it was crashing.

(node:3848) UnhandledPromiseRejectionWarning: Error: 400: Bad Request: message is not modified at buildConfig.then.then.then.then (D:\apps\bot\node_modules\telegraf\core\network\client.js:235:17) at at process._tickCallback (internal/process/next_tick.js:118:7) (node:3848) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1) (node:3848) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code. code :

app.action('start', (ctx) => {
    http.get('http://localhost:3000/api/questions', (res) => {
        //res.setEncoding('utf8');
        let rawData = '';
        res.on('data', (chunk) => {
            rawData += chunk;
        });
        res.on('end', () => {
            try {
                data = JSON.parse(rawData);
                i = Object.keys(data).length;
                ctx.editMessageText('Choose one of the options:', 
                Extra.HTML().markup(m => m.inlineKeyboard([
                    m.callbackButton(data[x].Q1, 'plus1'),
                    m.callbackButton(data[x].Q2, 'plus2')
                ], {
                    columns: 1
                })));
            } catch (e) {
                console.error(e.message);
            }
        });
    }).on('error', (e) => {
        console.error(`Got error: ${e.message}`);
    });
});

app.action('plus1', (ctx) => {
    if (x < i) {
        answer[x] = 1;
        ctx.editMessageText('Choose one of the options:', Extra.HTML().markup(m => m.inlineKeyboard([
            m.callbackButton(data[x].Q1, 'plus1'),
            m.callbackButton(data[x].Q2, 'plus2')
        ], {
            columns: 1
        })));
        x++;
    } else {
        ctx.editMessageText('Finished :', Extra.HTML().markup(m => m.inlineKeyboard([
            m.callbackButton('Result', 'result')
        ])));
    }
});

app.action('plus2', (ctx) => {
    if (x < i) {
        answer[x] = 2;
        ctx.editMessageText('Choose one of the options', Extra.HTML().markup(m => m.inlineKeyboard([
            m.callbackButton(data[x].Q1, 'plus1'),
            m.callbackButton(data[x].Q2, 'plus2')
        ], {
            columns: 1
        })));
        x++;
    } else {
        ctx.editMessageText('Finished :', Extra.HTML().markup(m => m.inlineKeyboard([
            m.callbackButton('Result', 'result')
        ])));
    }});

app.action('result', (ctx) => {
    ctx.reply(answer);
});
app.startPolling();