If you are installing Splice and run into an error/issue there are a number of factors that could be causing this.
Please delete the .dmg file you downloaded and download another installer directly from: https://splice.com/download
Double check you are using an account with Admin privileges, if you are using a computer with multiple OS user accounts make sure Splice isn't already in the Applications folder.
Make sure there are no network monitoring/anti-virus apps that would be blocking Splice from installing (Little Snitch, Avast, CCleaner, Bit Defender etc....)
Try creating a new User and give it Admin privileges to see if Splice can install.
Make sure there are no network monitoring/anti-virus apps that would be blocking Splice from installing like Norton, Windows Defender, McAfee, Avast, CCleaner, Bit Defender etc....
There are known issues with anti-virus blocking the installer, try temporarily uninstalling your anti-virus to rule it out completely.
Double check you have this component installed:
Microsoft .NET Framework:
If your password is working on the website but not the desktop app, this is usually caused by anti-virus/network monitoring apps blocking the credentials. Please temporarily disable/uninstall any software that could be blocking the Splice client and attempt to log in.
If you are still having issues installing take a screenshot of any errors and send it to firstname.lastname@example.org