Electronic certificates on Android mobiles
Skip information indexAndroid. Error when importing a .cer copy
The error occurs when importing an invalid copy of a certificate, usually made from Internet Explorer, with a .cer extension. Valid extensions are .pfx and .p12.
If you try to import a copy with a .cer extension to the device from email or the default browser on Android, the system does not know how to manage the file and offers applications that do not allow importing.
If you try to import a .cer copy from a file downloaded to the device as an email attachment or downloaded from another type of external storage media, such as an SD card, the Import wizard only allows you to choose .pfx or .p12 certificates, therefore, the .cer copy is not shown in the list and cannot be imported.