The “(402) Payment Required” message will concern an overdue invoice.
It is advised to check this in the “Invoices” screen on Invantive Cloud.
The “callback not valid” is related to the transition from the domain invantive.com to invantive.eu as described in Van invantive.com naar invantive.eu. A solution will be sought for this problem. The current workaround is to manually rewrite the URL to “cloud.invantive.com” instead of “cloud.invantive.eu” after logging in.