{"id":11384,"date":"2026-01-06T03:36:34","date_gmt":"2026-01-06T02:36:34","guid":{"rendered":"https:\/\/prosteit.pl\/?post_type=baza-wiedzy&p=11384"},"modified":"2026-01-07T13:37:27","modified_gmt":"2026-01-07T12:37:27","slug":"why-the-qualified-signature-does-not-work","status":"publish","type":"baza-wiedzy","link":"https:\/\/prosteit.pl\/en\/knowledge-base\/why-the-qualified-signature-does-not-work\/","title":{"rendered":"Qualified Signature Not Working? Common Causes and Quick Solutions"},"content":{"rendered":"
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A qualified signature can stop working at the most inopportune moment: during submissions to the Social Insurance Institution (ZUS), ePUAP, KSeF, JPK, tenders, contracts. The problem usually isn't a "broken signature," but rather a minor change in the system (update, driver, browser, permissions) that blocks the signature.<\/p>\n

Below you will find the most common causes and a checklist to help you quickly narrow down the source of the problem.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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What does the problem look like? Common symptoms<\/h2>

What does the problem look like? Common symptoms<\/strong>
\u2022 The browser does not see the certificate \/ does not show the signing option
\u2022 Token\/card is not detected
\u2022 The signing "goes around" and nothing happens
\u2022 I get a signature error or certificate error
\u2022 It worked yesterday, it doesn't work today
\u2022 It works on one computer, but not on another
\u2022 Does not work in RDP \/ on server \/ in virtual machine<\/p>

It is worth determining right away where you are signing:<\/strong>
\u2022 In the browser (e.g. ePUAP, tender platforms)
\u2022 In the signature provider application
\u2022 In the accounting\/ERP program
\u2022 Via Remote Desktop (RDP) or on the server<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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What could be the reasons why your qualified signature is not working?<\/h2>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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1. Windows\/browser update changed the behavior of the signature component<\/h2>

After Windows Update<\/b> or update<\/a><\/b> Chrome\/Edge\/Firefox may change permissions, add-on\/plug-in integration, or security settings.
What to check:<\/strong>
\u2022 Check the signature in another browser (Edge \u2194 Chrome)
\u2022 Check with another Windows user profile<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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2. The certificate has expired or the token\/card has been blocked<\/h2>

The simplest reasons occur most often:
\u2022 The certificate has expired
\u2022 After several incorrect PIN attempts, the token may get blocked
What to check:<\/strong>
\u2022 Check the validity of the certificate in the signature provider's application<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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3. Token\/card not detected - driver, USB port, reader<\/h2>

The reasons are sometimes trivial:
\u2022 The driver was not installed correctly
\u2022 Windows replaced the driver
\u2022 USB hub\/docking station problem
\u2022 The service responsible for the token does not start
What to check:<\/strong>
\u2022 Connect the token directly to the USB port on your computer (without a hub\/dock)
\u2022 Change USB port
\u2022 Check operation on another computer<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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4. Conflicting signatures or blind repairs\u201e<\/h2>

If different signature components were installed on the computer (or "someone installed whatever they wanted"), they may conflict with each other:
\u2022 Libraries and add-ons
\u2022 Background services
\u2022 Certificate configuration
Effect:<\/strong> random behavior, errors, or "sometimes it works, sometimes it doesn't.".<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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5. The platform (e.g. ePUAP\/tenders) is sensitive to security settings<\/h2>

Some signature platforms are sensitive to:
\u2022 Browser configuration
\u2022 SmartScreen\/protection
\u2022 Blocking components from starting
\u2022 Specific environment settings
Usually the following approach helps:<\/strong> diagnosis + correct configuration, not multiple reinstallations.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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6. Signature in RDP \/ on the server \/ in the virtual machine<\/h2>

In companies, the signature is often supposed to work on the accounting server or in a remote session.
Problems usually arise from:
\u2022 No USB redirection
\u2022 Security Policy
\u2022 Permissions
\u2022 Differences in configuration between the local computer and the server<\/p>

If the signature is to work in RDP\/VM, it is worth setting it up properly - makeshift ones often show their face at the least appropriate moment, e.g. 15 minutes before the deadline for submitting the signature (we have already saved ourselves from such situations).<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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What to do at the beginning \u2013 start without worries<\/h2>

1. Restart your computer (signature services can get stuck).
2. Plug the token into another USB port, preferably directly into the computer.
3. Check on another computer (you will immediately know whether the token or the system is to blame).
4. Check the validity of the certificate in the signing application.
5. Try a different browser (Edge\/Chrome).
6. If you are signing in RDP: check USB device redirection.<\/p>

If it still doesn't work after this, the problem most likely lies in drivers, system components, permissions or security policies, and it's worth approaching it methodically to avoid additional work and messing up the configuration.<\/p>

What to prepare for a quick diagnosis<\/strong>
\u2022 Signature Provider (e.g. Certum\/Sapphire<\/a>, KIR, EuroCert, Asseco<\/b> e.t.c.)<\/b>
\u2022 Windows 10\/11 + whether it is a laptop\/PC
\u2022 Where do you sign (ePUAP\/KSeF<\/a>\/JPK\/application)<\/b>
\u2022 Is the problem on one or multiple stations?
\u2022 Does this apply RDP\/Server\/VM<\/b>
\u2022 Error text (preferably a screenshot)<\/p>

You can contact us with this information and we will do our best to solve your problem.<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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FAQ - questions and answers<\/span><\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t
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\n \n \n Does a qualified signature work without the Internet?<\/span>\n\n \n
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The token itself works locally, but most platforms and signing processes require a connection to a service\/service, so the lack of internet can look like a "broken signature".<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n \n

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\n \n \n Is it possible to have a signature on the accounting server?<\/span>\n\n \n
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Yes, but it needs to be set up properly (device redirection, permissions, environment configuration).<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n \n

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\n \n \n Is reinstalling everything a good idea?<\/span>\n\n \n
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Sometimes it helps, but often it makes the situation worse, as component conflicts and system clutter inevitably result. The quickest way is to run a few tests (different browser, different computer, direct USB) and only then decide what actually needs to be fixed.<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n \n

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\n \n \n Is it possible to use one signature for several people?<\/span>\n\n \n
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A qualified signature is assigned to a specific person. Technically, the token can be re-linked, but formally, the signature always identifies the certificate owner. This is a common organizational mistake in companies \u2013 it's better for signers to have their own signatures.<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n \n

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\n \n \n Can I install the signature on multiple computers?<\/span>\n\n \n
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You can use the same token on different computers, but each computer must have the correct components\/drivers installed. In practice, it's worth standardizing workstations so that signatures work predictably across the entire company.<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n \n

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\n \n \n The qualified signature in P\u0142atnik does not work<\/span>\n\n \n
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Most common: token\/reader driver, signature component, Windows update, conflict after installing different versions of signature software, or permissions problem on the computer.<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n \n

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\n \n \n The signature in P\u0142atnik works on one Windows account, but not on another<\/span>\n\n \n
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This may be due to permissions, component access, per-user or per-machine installation, or where the program stores its configuration. It's also common in companies to sign on an account without local permissions.<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n \n

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\n \n \n I'm trying to authorize myself to KSeF, but the browser doesn't see the signing certificate<\/span>\n\n \n
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Most common causes include a change after a browser update, a component blockage, an add-on conflict, or a lack of access to a certificate in the system. It's worth checking in Edge and Chrome, as well as with a different Windows user profile.<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n \n

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\n \n \n Can antivirus\/EDR block a qualified signature?<\/span>\n\n \n
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It might. Sometimes, the protection is blocking a component, driver, or browser integration. If it suddenly stopped working after a security update, it's worth checking the logs\/events and exceptions\u2014rather than reinstalling everything from scratch.<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n \n

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\n \n \n Do you help with such problems with qualified signatures?<\/span>\n\n \n
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Yes. Such situations are classic "fires" that can bring accounting, HR, or the document signing process to a halt. Our team helps companies with similar issues every day: qualified signatures, certificates, browser configuration, token drivers, RDP\/VM work, component conflicts, and update effects.<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n \n

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\n \n \n Can such a problem be solved remotely?<\/span>\n\n \n
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In many cases, yes, as long as we have access to the computer\/environment via the remote assistance application and can check the configuration. If the problem turns out to be hardware-related (token, reader, USB port), we suggest simple tests that immediately narrow down the cause.<\/p> <\/div>\n\n <\/div>\n\n <\/div>\n\n