It is safe to close that dialog (OK to aknowledge), and almost certainly PingPlotter will continue collecting data without problems.
Whenever an error like this occurs, some debugging information is written to a file in your PingPlotter install directory - the file is called PingPlotter.rip. Can you send that file to
support@pingplotter.com so we can track down the problem? Once we've got that file, we'll let you know what caused it and what affect it has. We *might* need some more details from you, but won't know until we see the .rip file for this.
If this is a reoccuring problem that is causing you difficulties, we'll help solve this for you, one way or another.
Thanks for the report.