Re: MPLAB X v5.45 for mac
Just tried your link with the same results using Safari.
I was able to download the whole file for linux and windows using Safari. I'm running 10.15.7 on mac mini and 10.15.6 on mac book pro. I think it might be because I'm running catalina.
I copied your link into firefox, this time it asked me to open or save, chose save. SUCCESS! I think the failure from firefox earlier may of been it was opening the file rather than downloading it.
5.45 is currently installing.