If, when trying to sign in Portafirmas, any of these errors appear, please verify that you are using the latest version of Autofirma. If you already have the latest version installed, carry out the following adjustments:
On Windows, at the bottom in the search magnifying glass on the taskbar, type Autofirma and run the programme.
In Tools→Preferences→General, under Network Settings click on “Trusted Domains”. In the window that opens, type portafirmas.upm.es in the text box and click “OK” to close the window. Click “OK” again to close the preferences window.
In Tools→Preferences→Network Settings→Configure proxy you will access the proxy configuration.
Next, select “Use system proxy settings”.