Install IOS236. After that is done, run the Hemers installer, and instead of selecting IOS249 to run the installer, select IOS236 instead.
IOS236 - download, you will need HBC 1.0.7 or higher to install that.
Maybe later I'll post a IOS236.wad from the IOS236 installer v5.
If you cannot get the IOS236 installed then you may want to install cIOS38 rev17 to use the Hermes installer. I'll bet you installed cIOS rev19 or rev20 with a base that is not 38.