Weird Crashing Error

[u/killerbeex15]

Lately Ive been getting a weird error after loading books onto my kindle fire. Im loading the books as epib which in the past has worked great. The error happens whn i start reading the books it suddenly freezes and I usually have to either wait 3-4 min for it to reset or I have to do a hard reset.

Not sure if this is an error from calibre or from kindle? What should my next steps be?