The reason I'm still on an older version is I sometimes like to have 2 independent instances of hfs running on different ports but last time I upgraded that was not possible, the 2nd opened hfs would swap the html with the 1st or visa versa, somehow they were intertwined instead of independent of each other.
You should keep in mind that to have 2 independent instances of HFS running, you must have a copy of HFS.exe in 2 different folders and each instance should save the configuration stored in a .ini file (also known as portable mode). You could do that, by going (in Expert mode) to
Menu > Save options > to file. This is the way to go to not 'mix' or swap the HTML or the templates of one version with another. Another thing: before upgrading, always make a full backup of your HFS folders. If you want to start from zero in portable mode, you could put an empty hfs.ini along with the HFS.exe executable, and HFS will save all the configurations there.
If only after doing those steps the error continues, then perhaps you could have found a bug that should be fixed (before HSF v2.4 is released). The best thing you can do is share privately with
Rejetto (by sending him an email to
a@rejetto.com or a private message
here), all the details and the steps to reproduce that error (he will confirm you if that is a bug of HFS or not).
Your contribution on this, is important and makes HFS a even greater software.