Is this a new keystore or are you trying to import a keystore you already have?
For a new keystore, fill in the keystore details as described by the GM:S docs:
Name: This is the name of the KeyStore file. Note: This is not your name or the company name, but the name of the file to be generated!
Password: Your security password for the KeyStore file which must be at least six characters long.
Alias: This is another name that can be used for the KeyStore file and should be different to the name entered above.
Password: The password for the alias file. Should be the same as the Name password.
Common Name: This would normally be your name.
Organisational Unit: The department within the company that you are a part of.
Organisation: The name of your company.
Location: The name of the town or city where you are based.
Country: The standard two letter code for the country where you are based.
Then click on generate to create the keystore file.
(Always keep a backup of this file and the keystore details)
If you are not sure on what to enter in a field, let us know so we can help you.
If you are importing a keystore file:
Browse for or enter the location of the keystore under 'Private Keystore File', then enter the details of this existing keystore and click OK. DO NOT click Generate in this instance.