i have downloaded two trial versions of ReefMaster to see if it can do what i need it to do with my Lowrance side scan images for fresh water bass angling.

ReefMaster Sonar Viewer will accept and open my sonar.sl2 files whilst the ReefMaster V1.8 says that there is an error.

any ideas why?

Hi,
It looks as if you may be trying to open an SL2 file when ReefMaster first starts up. At this point, ReefMaster is expecting a ReefMaster DataBase file (.rmdb), which can hold information about a number of different sonar logs, waypoints, maps etc.
I suggest that you take a look at the getting started page of the manual, and also the workspace manual page for a basic grounding in the ReefMaster architecture. If you then follow the make a map tutorial you will see how sonar tracks can be imported for display in ReefMaster.

Many thanks, i will go through that and let you know if i still have an issue:)