******************* This email originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list https://spam.ic.ac.uk/SpamConsole/Senders.aspx to disable email stamping for this address. ******************* Hello everyone, I tried running an Adjoint Stability Analysis including Dongs convective outflow BC enforced through a Robin type specification as detailed in the user guide. I use a 2.5D expansion with version 5.7.0 and obtain satisfactory results with a high-order pressure BC. However, as I switch to a Robin BC, the following error appears: double free or corruption (!prev) ...indicating segmentation violation. I've attached some files of a MRE, which is basically just a cylinder at Re = 42. Is there anything wrong with my setup? Any help would be much appreciated. Best, Alex Gesendet mit [Proton Mail](https://proton.me/mail/home): Ein sicherer E-Mail-Dienst.