I have not been able to reproduce this. So, I decided to check which extension has the largest dependency list. And sure enough, it is Xfce4.tcz.
So, I begin with appbrowser, and sure enough, the dreaded "An Error Occured" occured!
So, I reboot and try with several other options, window managers, etc. I even tried slowing down between downloads and still failure everytime.
Come to find out that Xfce4 depends on fortune-mod.tcz which has a bad md5sum file in the repository. This was causing the failure.
Fixing the md5sum issue in the repository, fixed the problem. After many attempts, even with the largest dep file, Xfce4, I cannot reproduce a failure.
Lately, there has been reported several file consistency issues in the repositories.
I will focus some time and creating some audit tools to prevent future failures that would appear to be an appbrowser problem.
I will also work to improve the content of the error message(s) in appbrowser. Still the failure that I was observing is something that appbrower nor the remote user would be able to handle.