This translation is fairly straightforward except for the part about accessibility. 'no longer accessible' is roughly translated to 'no longer can be found' to make it sound more smooth in Amharic. It says sorry and informs the user that the chat (no common way to translate chats so used a relating term which is discussion) can no longer be found. The meaning is wholly kept from the English version.
Some of the issues I fixed are the reference 'this' was not correctly translated in the previous suggestions. The word 'chat' was also not correctly translated, it was translated as a message, I changed that to a better-relating term which is discussion.

it sounds natural and its understandable by native amharic speakers