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Seeing "Failed to establish connection to the server" or "Kindly restart the emSigner" while signing GST returns with your DSC? Your browser can't reach the emSigner utility on your computer. Here's how to fix it in about 5 minutes.
Error
https://127.0.0.1:1585
Failed to establish connection to the server. Kindly restart the emSigner.
Quick fix
When you click "Sign with DSC", the GST website talks to a small program on your own computer called emSigner, at https://127.0.0.1:1585. If that conversation fails, you get this error. There are four usual reasons.
It doesn't start automatically after every restart. If there's no emSigner icon in your system tray, the portal has nothing to connect to.
Older versions listened on port 1645. The GST portal now connects on 1585, so an old install never answers.
emSigner uses a local security certificate. Until you allow it once in your browser, the connection is silently blocked.
Antivirus, a firewall, or another signing utility can block or occupy port 1585.
Follow these in order. Most people are signing again after step 4.
Open Control Panel → Programs and Features (or Settings → Apps), find emSigner and uninstall it. This removes the old version that listens on port 1645. Restart your computer afterwards.
Download it only from the official GST Document Signer page (also linked under Register/Update DSC after you log in). Don't reuse an old installer saved on your computer. Install it.
Right-click the emSigner shortcut and choose Run as administrator. Wait until it shows that the service has started, and check that its icon appears in the system tray near the clock.
Open a new tab in the same browser you use for GST and go to the address below. You'll see a privacy warning: click Advanced, then Proceed to 127.0.0.1 (unsafe). This is your own computer, so it's safe.
https://127.0.0.1:1585
Open in new tab →
Using Firefox? Firefox keeps its own certificate list, so accept the exception inside Firefox even if you already did it in Chrome.
Insert your DSC USB token, go back to the GST portal tab and refresh it (or log in again). Now click Sign with DSC, select your certificate and enter your token PIN.
If emSigner worked last year and suddenly stopped, this is usually why.
| Old emSigner | Current emSigner | |
|---|---|---|
| Local address | https://127.0.0.1:1645 | https://127.0.0.1:1585 |
| Works with today's GST portal? | No | Yes |
| What to do | Uninstall it | Install from the GST portal and run as administrator |
Go through this list before reinstalling again.
We fix GST emSigner and DSC errors remotely over AnyDesk or a call, even if we didn't issue your DSC. If your certificate has expired, we can issue a new one the same day.
Your browser is trying to reach the emSigner utility running on your own computer (127.0.0.1 is your computer, 1585 is the port emSigner listens on) and cannot connect. Usually emSigner is not running, is an old version, or the browser has not yet trusted its local security certificate.
It is the same problem. The GST page could not reach emSigner. Close emSigner from the system tray, start it again with Run as administrator, open https://127.0.0.1:1585 once in your browser and click Proceed, then refresh the GST tab.
Older emSigner versions used port 1645. Current versions from the GST portal use port 1585. If an old version is still installed, the portal and emSigner are on different ports and cannot connect, which is why uninstalling the old version first matters.
Yes, for this address. 127.0.0.1 is your own computer, not a website on the internet. The warning appears only because emSigner uses a self-signed local certificate. Only do this for 127.0.0.1, never for an unknown website.
Chrome, Edge and Firefox all work once you have opened https://127.0.0.1:1585 and allowed it. Firefox keeps its own certificate list, so in Firefox you must accept the exception inside Firefox itself, even if you already did it in Chrome.
Check that your USB token is plugged in and its driver is installed, that your DSC is registered on the GST portal under Register/Update DSC, and that the DSC has not expired. Antivirus or firewall software can also block the local port, so allow emSigner through it.
Usually not. This is a software connection problem on your computer, not a problem with the certificate. You only need a new DSC if yours has expired or the token is damaged or lost.