Stata repeated-measures ANOVA returns error code r(9131)

[Gilbert Lazarus]

Hi, I'm doing a repeated-measures analysis with this sample dataset:

This is the code of the analysis and returns of the error code:

anova y a / id|a x_days a#x_days if treatment == 1, repeated(id x_days)
r(9131);

but when I search what r(9131) is, I can't find any reference to it.

fyi, I did the same exact commands with the other groups (the other groups have 3 measurements i.e., 30, 60, 90, while this group has 4 measurements i.e., 30, 60, 90, 180). Am I missing something?

TIA

[Rich Goldstein]

here is the information from the manual on all return codes from 9000 up: "Various messages, all indicating an unexpected system failure. You should never see such a message. If one occurs,

save your data, and exit Stata immediately. Please email [email protected] to report the problem"

[Brent Hill]

For what it's worth, I copied the 12 records in your example dataset and ran the command exactly as you have it (minus the if treatment==1 qualifying statement), and it ran just fine. Side note: I don't think you need to put id in the repeated() option. But that wasn't causing the issue.