I downloaded the file for the program and it won't open, it just pops up an error like "windows cannot access the specified device path or file". What do I do?

See issue here as well: https://forum.fopnu.com/support/46

You are not alone - here is what happened essentially:
"I had the exact same issue happen with Tixati (twice)- where it was automatically uninstalled and this week after running fopnu for nearly 6 months it was uninstalled upon a reboot automatically with no warning.

Fortunately when you re-install, the configurations are restored and not reset."

Solution: Reinstall the program

Hi, in my situation I downloaded portable v1.61 version and I use it in 2 virtual machines windows 7 and win 8.1 the downloads dir is located in a windows host, the .exe I use in another folder in the same host (so exe and downloads are acessible though "virtual" network between vms and host I didn't map in windows I use vmware "shared folders") and everytime I open fopnu appears an error in any windows without much explanation why.
I solved this problem just changing the name "fopnu_portable_mode.txt" file to "fopnu_local_instance_check.txt". I liked to also use the software in host but I notice fopnu automactically change the downloads folder and when I use fopnu inside a vm the downloads folder changes again, so in this case I decided to use fopnu only inside the vms. I have just 1 folder with the exe and just 1 folder for the downloads, all settings will be auto-saved inside the exe dir. I hope this helps anyone because I didn't had help from fopnu channel (through titaxi channels list) and nowhere else.

Regards, Mister X