I apologize for the brief answer. As others have assisted with clearing things up, it should also be noted that in the 2.x days, the move to 2.3 from 2.0 was really 2 or 3 full platform updates. That phone just won't handle it. I had a Motorola Droid that could hardly handle the last OS that was released for it (2.3 I believe), and it was a better device than the Eris.
To humor you, I did a quick search and came up with the XDA dev forum for that device that seems to show a 4.1.1 ROM was available for that device (if the mirror is still hosting the download, and some devices had a touchscreen that did not work on that ROM)
https://forum.xda-developers.com/htc...is/development The Play Store page for Alfred does not list an actual minimum Android version, it just says "varies by device".