Thanks for reaching out to us about this, and I'm sorry to hear about the trouble you're running into. VoodooPad 5 is currently available on our website here and is purchased separately from Voodoopad 4. If you would like to download VoodooPad 4, you can download a copy of version 4.3.6 here.
If you would like to convert your documents to VoodooPad 5, we highly recommend backing them up before opening them in VoodooPad 5, in case of any computer issue or unforeseen issue with the upgrade process. If you run into any trouble, please also let me know and I would be happy to take a closer look.
Due to the nature of Primate Labs acquiring VoodooPad after VoodooPad 5 was released, it is difficult for us to provide extensive support on previous versions. However, I would like to take a closer look at this issue. Could you describe (or post a screenshot of) what it looks like when VoodooPad is stuck while searching? Is there any error messaging, like "0 pages found"? If you create a new page or edit an old one, does that page appear in the search? Some non-alphanumeric characters (e.g. #) are not supported for searching in all contexts, so for troubleshooting purposes please use simple alphanumeric characters.
In addition, could you let me know which version of macOS/OSX you are using?