Not sure what could be happening. By “previous version”, do you mean 1.4.x, 1.5.x (where x<14), or 2.x?
I assume that if you kill the process and try again, the same thing happens?
Was your last project (in the previous version) based on a Paratext project, a text release bundle, or a Glyssen script?
As a first diagnostic step, maybe you could try temporarily renaming the folder of the last project you had open (in C:\ProgramData\SIL\HearThis). At least that way, if HT is hanging up because of something corrupt in the project data, it should present you with an Open project dialog. If you can open some other project, then we’ll know it’s probably a project-specific problem rather than an installation problem. I don’t know a whole lot about what all was done in version 2, but if you’re opening the same project, I suppose it’s possible that some change made in version 2 causes the project to no longer be compatible with older versions of HT.