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[FIXED] (B1900.8) Cannot open scenario: "Object reference not set to an instance of an object"
Posted: Thu Aug 27, 2026 10:50 pm
by oiajz
Upon trying to open a scenario which I have been working on, my computer freezes for maybe half a second and the below error appears. I know the devs prefer clean scenarios for bug reporting but I have had this happen before, maybe a year ago, and both times I have had between 1500-3000 units, so maybe it is linked to that? Either way I have no idea what caused it so this is the best that I can offer. I have included the exception log as well.
- Screenshot 2026-08-27 232752.png (14.63 KiB) Viewed 559 times
Re: (B1900.8) Cannot open scenario: "Object reference not set to an instance of an object"
Posted: Fri Aug 28, 2026 2:25 am
by Raptorx7_slith
Thanks, logged as 0017585
Re: (B1900.8) Cannot open scenario: "Object reference not set to an instance of an object"
Posted: Fri Aug 28, 2026 7:09 am
by Nikel
Similar or the same xml errors than in this previous report.
https://forums.matrixgames.com/viewtopi ... 7#p5281837
Re: (B1900.8) Cannot open scenario: "Object reference not set to an instance of an object"
Posted: Fri Aug 28, 2026 9:23 am
by Deserere
hi oiajz
the issue was caused by a corruption in the scenario file (pretty random I think) and a field that was not sanitized correctly before serialization.
A fix for the sanitization will be included in the next update release.
In the meantime I manually recovered your scenario.
Attached the file, you should be able to open it now.
Re: [FIXED] (B1900.8) Cannot open scenario: "Object reference not set to an instance of an object"
Posted: Fri Aug 28, 2026 10:41 am
by oiajz
Thank you for fixing it, much appreciated!
Re: [FIXED] (B1900.8) Cannot open scenario: "Object reference not set to an instance of an object"
Posted: Sat Sep 05, 2026 1:19 pm
by oiajz
I have had the same issue happen again with the same scenario after it was manually fixed, what can be done? I feel like requesting it to be recovered again is asking too much of the devs but at the same time I have spent too long on this to just throw it away.
Re: [FIXED] (B1900.8) Cannot open scenario: "Object reference not set to an instance of an object"
Posted: Mon Sep 07, 2026 7:19 am
by Deserere
Wait for the new update release so that the issue will not happen again before continue working on your scenario, saving with your current version can break this specific scenario.
As an extra test I opened it with my version of CMO, just opening it and then save it fixes the issue.
Attached
Re: [FIXED] (B1900.8) Cannot open scenario: "Object reference not set to an instance of an object"
Posted: Mon Sep 07, 2026 8:37 am
by oiajz
Thank you so much, sorry to have been a pain. I will wait for the update as you suggested before messing around with it again.