Hi @sforssell. Thanks for being part of GoDaddy Community! Do you have the option to use the pop-up compose window chosen by chance? It could be that your browser is interpreting the pop-up as a file download somehow. If so, I'd recommend turning this option off to see if that helps. The process to change the setting depends on which view you're in.
Options (gear icon)> More options > uncheck "Always open composer in a separate window" > click Save
Settings > Display settings > Composing tab > uncheck "Use Pop-up Compose" > click OK