Hello David, Please create an issue for this kind of crashes on our tracker, its much easier to track and discuss. Cheers, Henning *From:* sr-users &lt;sr-users-bounces(a)lists.kamailio.org&gt; *On Behalf Of *David Escartín *Sent:* Friday, May 21, 2021 1:15 PM *To:* Kamailio (SER) - Users Mailing List &lt;sr-users(a)lists.kamailio.org&gt; *Subject:* [SR-Users] core kamailio 5.4 Dear all we have seen a core in a kamailio instance today, i attach you the bt in dropbox https://www.dropbox.com/s/3dg72cbuz7nvx5b/core_kamailio_21mayo?dl=0 https://www.dropbox.com/s/iyko32fwfxj8aam/core_kamailio_21mayo_2?dl=0 seems there might be a relation async module when delaying a request after communicating with the rtpengine ?¿ could you please take a look? thanks a lot and regards david -- <http://www.sonoc.io/> David Escartín NOC engineer *www.sonoc.io* <http://www.sonoc.io/> [image: LinkedIn] <https://www.linkedin.com/company/sonoc> [image: Twitter] <https://twitter.com/sonoc_> [image: Facebook] <https://www.facebook.com/SONOCio/> This e-mail is for the exclusive use of its recipients and may contain business secrets or other confidential or privileged information. Any unauthorised use, copying, publication or distribution of this e-mail is strictly prohibited. If you are not the intended recipient, please inform us immediately by replying to this e-mail and delete it, including any attachments or copies on your system. In accordance with the GDPR (EU) 2016/679 and the LOPDGDD 3/2018, we inform you that this e-mail address and/or any other personal data you have provided us with will be treated by SONOC with absolute confidentiality and with the only purpose of providing you with the requested services, due to your condition as a client, supplier or because you have requested information from us at any time. These data will only be kept for as long as required to comply with legal obligations. You can exercise your rights at any time by sending an e-mail to: *dataprotection(a)sonoc.io* &lt;dataprotection(a)sonoc.io&gt;*.* &lt;dataprotection(a)sonoc.io&gt;