To load MH Tri you need IOS223 (37 merge 38), not IOS224.
I was following these instructions - the problem starts at step 10. I have done the previous steps already.
CODEUse cios222 v4 base37/38
1. Start HomeBrew Channel and start the cIOS 222 Installer
2. Read the warning message and push A
3. Select IOS249 to perform the install with D-pad left/right and push A
4. Select to Install Custom IOS 222 and select IOS38 merged with IOS37
5. Wait for download and installation to complete
6. Start HomeBrew Channel and start the cIOS 222 Installer again
7. Select IOS249 to perform the install again
8. This time select Custom IOS 223 and select IOS38 merged with IOS60
9. Finally, use IOS249 to perform install again.
10. Select Custom IOS 224 and use IOS57 as base.
*IOS223 gives you an alternative option for merged IOS in this way. It is exactly the same as IOS222 otherwise.
*Experiment with other merges or not merging at all if neither of the options provided here work for you,
or cios249 rev19 base 37 or 223 v5 37 base any of these should work