I'm just getting started. I tried installing the host software and all the required java components. When I attempt to launch reprap-host.bat, I get:

C:\cygwin\home\Greg\dev\reprap\reprap-host-20080523>java -cp ".;.\reprap.jar;C:\Program Files\Reprap\;C:\Program Files\Reprap\reprap.jar;C:\Program Files\Java\shared\*" -Xmx384M org/reprap/Main Exception in thread "main" java.lang.NoClassDefFoundError: gnu/io/PortInUseException

This sure sounds as though it is somehow not finding the rxtx libraries. Am I right? I didn't see anything in the instructions about modifying the CLASSPATH or anything. Do I need to add something?

Yes looks like Java cannot find the rxtx libs

I can replicate this error if I move RXTXcomm.jar out of ...lib\ext\

I presume you are using windows, double check all the three required rxtx files are in the correct place [rxtx.qbang.org]

had a problem in the past, not reprap related, with more than one version of the JRE on the same machine not sure if this is the case here

My rxtx files:

Greg@Alice:/cygdrive/c/Program Files/Java
=>find -iname "*rxtx*" -exec ls -l {} \;
-rwxr-xr-x 1 Greg None 47421 Jul 27 10:49 ./jre1.6.0_07/bin/rxtxParallel.dll
-rwxr-xr-x 1 Greg None 77759 Jul 27 10:49 ./jre1.6.0_07/bin/rxtxSerial.dll
-rwxr-xr-x 1 Greg None 59464 Jul 27 10:42 ./jre1.6.0_07/lib/ext/RXTXcomm.jar

I think that's all the rxtx components, in their rightful places with reasonable permissions.

So is it possible my windows system isn't defaulting to the most recent jre for some reason? I have accumulated several jre's:

Greg@Alice:/cygdrive/c/Program Files/Java
=>ls
Java3D/ jre1.6.0/ jre1.6.0_03/ jre1.6.0_07/
jdk1.6.0_02/ jre1.6.0_02/ jre1.6.0_05/

that looks correct

try "java -version" (without speach marks ) at the console/command prompt

will tell you which JRE version you are 'defaulting' to

sorry other than that don't have any ideas

Hi everybody!

I have the same problem with my reprap-host.
I tryed to look, what version of jre does my windows use, but the window(where it should be shown) momentally disapears.

sorry for my english)) (i'm from Ukraine)

I was able to solve this problem by uninstalling my JDK along with all the different JRE versions on my system, then installing a fresh JDK and the latest JRE, and then re-applying the components needed for RepRap.

baster.89 - dont apologise for your english - its far far better than my ukrainian.
(I assume that is what your 'native' language is - mine in UK english.)

Thanks to everybody, but the problem remained...(
I tried to delete and reinsatall the JDK and JRE, but nothing has helped.((

Richard Benjamin:
I spoke english much much better some years ago. But now I forgot it, and can translate only one way easily (to russian). And translation to english is very hard for me now(..

I'm having the same problem. My java version is 1.6.0_17, according to java -version. Granted, 1.6.0_17 is not My default java version; 1.5.0_22 is. However, 1.6.0_17 is the binary invoked by the sh script.

Any additional tips would be greatly appreciated.

Any updates to this post? I have Java JDE 6 installed, but my "java -version" lookup brings back:

java version "1.3.1_01"
Java(TM) 2 Runtime Environment