[ul][li]Please test the digital signature on E:\DOPUS\dopushlp.dll to verify that the file itself is not corrupt.
[/li]
[li]Is E:\DOPUS where the USB copy is being run from, or is it an unrelated folder?
[ul][li]It might be left over from a previous USB copy.[/li]
[li]Or it could be the drive letter which the USB device used in the past but isn't using today.[/li][/ul]
[/li]
[li]When does the error message appear?
Is it as soon as you launch Opus?
[ul][li]How are you launching Opus?[/li]
[li]Is Opus configured to run any commands at startup? (Under Settings - Preferences / Launching Opus)[/li][/ul]
Or is it later on, when you do a particular action?
[ul][li]Which action is triggering the message?[/li][/ul]
[/li]
[li]Which version of Windows are you running the USB copy on? (It's exported from Windows 8 64-bit, but is it being run on the same OS, or on another OS?)
[ul][li]If it's Windows XP, which service pack is installed?
[/li]
[li]If it's Vista or above, what happens if you try to do something that requires UAC elevation?
e.g. Create a new folder under C:\Program Files. On a USB install, that should show an extra prompt, asking you to allow a component to be registered. (The component is dopushlp.dll, although it is not mentioned by name. If you aren't prompted, it may already be registered, and the registration may point to an old or incompatible version of the DLL. If so it is easy to fix.)[/li][/ul][/li][/ul]