even when I convert my file to a format that Mega accepts, erros keep occuring.
This is not very helpful. For example, what format did you try, how did you convert it, and what was the error?
IQ-TREE makes lots of different files. What you need is one that ends in .contree
, which is a consensus tree in Newick format. If you don't have that file, another one that should work ends in .treefile
, also in Newick format. Neither of those two files requires conversion for MEGA, but you may need to rename them so they end in .nwk
.
cp something.contree something.nwk
Now you should be able to open something.nwk
in MEGA without problems.