Corner case Connect issues on Chrome 45 and higher


In the majority of cases the Aspera Connect browser plugin works without issues on Google Chrome 45 and higher, but it may be that you have unusual settings configured or you’re running behind a proxy which can cause problems.

This article contains several corner case issues you may experience with Connect on Google Chrome 45 and higher, and steps for how to resolve them. If you are still unable to fix your issue, please contact Technical Support.

No PNaCl translator installed


PNaCl (Portable Native Client) is a key component that allows Connect to run in Chrome. Usually it is present in Chrome by default, but if you installed Chrome offline, or installed Chrome on a PC behind a web proxy, PNaCl may not have been installed or updated.

When this is the case you see the following message in the Console of the Chrome developer tools:

NativeClient: The portable Native Client (pnacl) component is not installed.
Please consult chrome://components for more information.


You can further verify this by navigating to chrome://nacl and checking that PNaCl translator is listed as Not installed:



Navigate to chrome://components and find pnacl. You will see that the version listed is


Try installing or updating it by clicking Check for update.

If you are behind a web proxy this will not work and you will need to install PNaCl manually.

Installing PNaCl manually

You will need to copy working PNaCl files over to the problematic system.

1. Obtain PNaCl files

Attached at the end of this article are PNaCl files for Chrome on Windows, Linux and Mac.

Alternatively, you can copy the PNaCl files from a working system over to the problematic system. You can find the precise path at which PNaCl is located by navigating to chrome://nacl and looking at the PNaCl translator path:

Usually the PNaCl files are located at the following, where <username> is the system user:

  • Windows: C:\Users\<username>\AppData\Local\Google\Chrome\User Data\pnacl\
  • Mac OS X: /Users/<username>/Library/Application Support/Google/Chrome/pnacl/
  • Linux: /home/<username>/.config/google-chrome/pnacl/

2. Copy the PNaCl files to the corresponding path on the problematic system

Copy the entire PNaCl folder (composed of files and subfolders) to the problematic system. The files within it are versioned and architecture dependent.

3. Restart Chrome

Native client is disabled


If you have Connect installed and are unable to download or upload files, you may have the Native Client plugin disabled. Native Client is the sandbox in Chrome in which the Connect application runs, so it needs to be enabled in order for Connect to function.

In cases where Native Client is disabled, you will see a blue banner at your server web interface with the message Aspera Connect is unable to launch, and a prompt for you to download the latest version even if you already have Connect installed.


To enable Native Client type chrome://plugins/ into the address bar in Chrome and hit enter. You will see a list of available plugins, and whether they are enabled or disabled.

In the following case, you can see that Native Client is disabled:


Enable Native Client by clicking Enable.



You can also check the status of Native Client at chrome://nacl/. Ensure that Portable Native Client (PNaCl) is set to Enabled.


If you return to or refresh the server web interface, you should now be able to successfully download and upload files with Connect.

Native Client flags or debug flags are enabled


The following message appears in the Console of the developer tools:


This is due to Native Client or Native Client debug flags being enabled when they should not be.


Navigate to chrome://flags and look for the settings shown below:


The settings should be configured as follows:

Native Client Disabled
Native Client GDB-based debugging Disabled
Restrict Native Client GDB-based debugging by pattern Debug everything except secure shell and the PNaCl translator.

These are the default settings, but if your browser has been configured differently, change them so they match the settings and picture above.

Antivirus problem


The Aspera web API for Connect allows the application to poll the status of the plugin using non-privileged ports over a HTTPS connection on

Some antivirus programs detect these polling operations and misinterpret them as attacks, and subsequently block the TCP channel:



Disable the antivirus program. If this doesn’t work, you may need to uninstall the program from your system completely.

Web proxy doesn’t allow local addresses


The Aspera web API for Connect allows the application to poll the status of the plugin using non-privileged ports over a HTTPS connection on

These polling calls will fail if you’re on Windows behind a web proxy and haven’t configured local addresses to bypass the proxy server.


Go to Control Panel > Network and Internet > Internet Options. Click on the Connections tab and select the LAN settings button.

Check the Bypass proxy server for local addresses option and click OK.


PNaCl files


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