Unable to start MinimWatch

[Lunn33]

Upgraded to latest version yesterday 4th January and MinimWatch will not run, Minimserver is fine and working.
Windows 10 and Java 1.8.0_111 (64 bit).
Tried removing and reinstalling Java and MinimWatch but all I get is a very brief message flashed on screen "Error: Could not find or load main class C:\Program Files\MinimWatch\lib\mwatch.jar"
Checked forum and similar problem for Blair2201 in 2015 but no solution confirmed.
jar extension is associated with java.exe.
Minimwatch is installed in Program Files rather than Program Files (x86) indicating also 64 bit version??

Any suggestions