Why do I get Nets error when signing Norwegian BankID?

Do you get this error code when you try to sign with Norwegian BankID?

The reason you are experiencing this error is:

• You have put on the Sign multiple documents with one signing key feature
• Your documents exceed the 200 character limit (spaces are not included in characters)
• Or unreadable characters are included in the document names (-, /, {, [,=, etc.)

You must therefore cancel the transaction as you cannot make any changes to an ongoing transaction (change document names or sign multiple documents with one signature - feature)

Solution 

There are three ways to solve this problem:

1. You take the Sign multiple documents with one signing key feature off (you can do this in the template, or on the signer when you are adding a new signer)
2. Change your document names so that they do not exceed 200 characters in total
3. Or remove the unreadable characters from the document names