# Otii Arc Pro - Core error 3221226505 **URL:** \ **Category:** Arc/Ace Pro\ **Created:** [November 22, 2023, 8:12am UTC](https://forum.qoitech.com/t/otii-arc-pro-core-error-3221226505/479 "2023-11-22T08:12:50Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![federico](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@federico](https://forum.qoitech.com/u/federico)\ **Post date:** [November 22, 2023, 8:12am UTC](https://forum.qoitech.com/t/otii-arc-pro-core-error-3221226505/479/1 "2023-11-22T08:12:50Z")
Hi all, I’m using the Otii Arc Pro device and the TCP Server API to conduct a rather long experiment campaign, but after about 3 hours the experiments crashed. In my script log I found the line “Undocumented error: {‘type’: ‘error’, ‘errorcode’: ‘Not ready’, ‘cmd’: ‘otii\_get\_active\_project’, ‘trans\_id’: ‘1808941’, ‘data’: {}}”, while in the Otii Server logs the line “Core error 3221226505”, followed by some “Failed to connect to Otii Core”. Moreover, the device under test shut down at about the same time that the error occurred in the script/server. I have used this script before and in that case everything went smoothly. The software version is “3.3.7”. What could be the cause of such error ? ---
**Author:** ![andreasolausson](https://avatars.discourse-cdn.com/v4/letter/a/e480ec/32.png) [@andreasolausson](https://forum.qoitech.com/u/andreasolausson)\ **Post date:** [November 23, 2023, 10:52am UTC](https://forum.qoitech.com/t/otii-arc-pro-core-error-3221226505/479/2 "2023-11-23T10:52:54Z")
Hi, we have fixed issues similar to this since 3.3.7. Please upgrade to the latest Otii 3.4.1 and if the error is still happening, file a support case here [User Management - Qoitech](https://www.qoitech.com/cases) and we will help you troubleshoot and fix this. Best regards, Andreas ---
**Author:** ![federico](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@federico](https://forum.qoitech.com/u/federico)\ **Post date:** [November 27, 2023, 8:08am UTC](https://forum.qoitech.com/t/otii-arc-pro-core-error-3221226505/479/3 "2023-11-27T08:08:39Z")
Thanks for your reply, I’ll try to update the software.