Not sure what you mean by “completing configurations” of the plug in. You shouldn’t have had to do anything except load it via WP admin install plug-in feature and activate it. Check your other plug-ins they may be causing the problems.
P.S. If you search the forums with keywords you can see that others have had issues with other Plugins or Themes that interfere with SLP and use Google maps, your error message sounds like this could be the issue, read the forum post below: