Unexpected reboot on a macbookPro with “Previous shutdown cause: -11”

Question

I have a 2020 macbookPro 64GB 16" . It shut down unexpectedly and I ran a log show command to find out the cause:

log show --predicate 'eventMessage contains "Previous shutdown cause"' --last 24h
Filtering the log data using "composedMessage CONTAINS "Previous shutdown cause""
Timestamp                       Thread     Type        Activity             PID    TTL  
2021-04-30 20:46:14.785443-0700 0xd8       Default     0x0                  0      0    kernel: (AppleSMC) Previous shutdown cause: -11
--------------------------------------------------------------------------------------------------------------------
Log      - Default:          1, Info:                0, Debug:             0, Error:          0, Fault:          0
Activity - Create:           0, Transition:          0, Actions:           0

The key of this is kernel: (AppleSMC) Previous shutdown cause: -11

From this page https://udcf.gla.ac.uk/~gwm1h/Error_Codes/Codes_0_to_-99.html the errror is:

qAllocErr               from MakeITable

What would be a fix in case this were to start to recur?

Answer 1

The error code list you have found is in no way applicable to your shutdown cause code. You cannot just find any error code list that happen to have the number -11, as these numbers are chosen completely arbitrarily by software developers and have no inherent meaning, so error -11 in one context means something completely different than -11 in a different context. The error you have found concerns QuickDraw, which were a 2D graphics API used in Macs running classic Mac OS (i.e. 20+ years ago).

You can find incomplete lists of shutdown cause codes here:

https://georgegarside.com/blog/macos/shutdown-causes/ Are OS X shutdown cause and sleep cause numbers listed/explained anywhere?

However, neither list will tell you what -11 means in this context.

There's really no way of telling what it means without asking Apple. And as such, there's of course also no way of telling you how to fix it given the information available to us.