Cannot Fix

[ETERN4LVOID]

I am trying to fix a vulnerable file but get this error:

Cannot fix CVE-2021-44832, Upgrade it

I have seen that I may need to upgrade the jar file but I am not certain how to do that, fyi the file in question is a file relating to the game "slay the spire".

Also what does "Trailing char < > at index 48" mean?
How can I fix these issues?

I also just wondered if I should be concerned about jar files the tool says are broken for some reason, the seem to fulfil their purpose though just regarded as broken.

Thanks