Steps to Reproduce:

• Use a link from our emailing (https://spenden.wikimedia.de/?skin=1&betrag=25.55&piwik_campaign=ma191124org&piwik_kwd=b3)
• Choose a payment method
• Click the submit button

Actual Results:
The button does not react.

Expected Results:
The button should lead you to the second page of the donation form

Tested on Windows 7, IE 11.0.9600.19540

Notes
Console log shows the error message

Object doesn't support property or method 'trunc'

while executing

amountInCents = Math.trunc( parseFloat( String( formValues.amount ).replace( ',', '.' ) ) * 100 );