If you have any problem with the softphone, Mizutech support most probably will ask you to send a detailed description and logs about the problem.

You can create a log in the following way:
-From the "File" menu open "Advanced settings" then go to the "Application" page
-Increase the loglevel to "Max loglevel" (or "including rtp log" if the problem is related to media/RTP) and click on Save
-Restart the softphone (File menu -> Exit, then start again) and reproduce the problem
-Go back to the application settings and click on the "View Logs" which will open the logs in notepad
-From notepad click on File menu -> Save as, and save your logfile for example on the desktop
-Send the logfile by email (attached) to support@mizu-voip.com

Note:
-If the problem is call related, then make sure to have only one call in the log. That one in which the problem was reproduced.
-Loglevel with "including rtp log" might affect call quality. It might be needed to trace RTP related problems and you should turn it off after you have sent the logs.
-In addition to the log file, Mizutech support might ask one or two SIP account valid on your server to be able to reproduce the problem