The “Invalid BIC”-error when trying to carry out a EUR withdrawals means means that your bank is not part of the network of SEPA-reachable banks. The list of participating banks is updated on a weekly basis. Our bank uses the list maintained and provided by the German Bundesbank in Frankfurt, Germany.
The full list of reachable BICs from the German Bundesbank can be found by clicking here.
If your bank is part of the SEPA network but you still get the error, this could mean that withdrawals to your bank are restricted because past withdrawals have frequently been rejected or returned.