Protocol error (Page.printToPDF): Show invalid printer settings error, thrown while printing pdfs

Steps to reproduce

• Puppeteer version: 6.14.7
• Platform / OS version: Ubuntu 18.04.5 LTS
• Node.js version: v14.8.0
• local-chromium: linux-782078

Prerequisites Have two similar methods, which generate pdf, calling page.pdf() Example functions:

async printFolderQrCode(folderId) {
    const page = await this.openNewPage();
    const pdfPath = ...;

    const uri = new URL(...t);
    uri.search = ...;

    await page.goto(uri);
    await page.pdf({ path: pdfPath });
    await page.close();
    return pdfPath;
  }
`
`
  async printDocumentTypeQrCodes() {
    const page = await this.openNewPage();
    const pdfPath = ...;

    const uri = new URL(...);
    uri.search = ...;

    await page.goto(uri);
    await page.pdf({ path: pdfPath });
    await page.close();

    return pdfPath;
  }

Execution Executed the functions in both ways sync and async (using Promeise.all())

Expected result? Two pdfs are stored on the fs, and the methods return their paths.

Actual result Sometimes, the execution results in failure, with exception thrown:

Error: Protocol error (Page.printToPDF): Show invalid printer settings error
      at /home/dbonchev/Documaster/wfc/software/automation/wfc-test-automation/node_modules/puppeteer/lib/cjs/puppeteer/common/Connection.js:208:63
      at new Promise (<anonymous>)
      at CDPSession.send (node_modules/puppeteer/lib/cjs/puppeteer/common/Connection.js:207:16)
      at Page.pdf (node_modules/puppeteer/lib/cjs/puppeteer/common/Page.js:1152:43)

In 2/3 of the executions, everything is OK, and pdfs are printed, but in 1/3 of the cases the error above is thrown. This anomaly has appeared, once I updated the puppeteer version @latest.

[koga021]

To resolve my problem, im using many of code (try/catch) validation and looping. Every important code, im using while with try/catch , and break with my code if it not return error on my try catch. Following this way, every error returned maping or not, go to my initial global looping and make all again and again.

async function(){
//global while true
while (true){
   try{
      //And more while(true) with try/catch with all parts of my code
     ///await puppeteer.launch , await page.goto, cut imagem, sender to s3, and database connection
     // all importants code i using while with try catch.
    break;
   }
   catch(error) {
      console.log("error, repeat all! initial code")
            
}


}

}

[joamag]

Found the original problem: We were calling window.print() at the start of the document load which creates a collision between puppeteer trying to “print” a PDF and the printing dialog created by Javascript call (window.print()).