Eclipse p2 update site



Hopefully someone has run into a similiar issue before and can suggest a fix. 


I've been trying to put together an update site for some internally developed nodes. The site displays correctly, I can select which features should be installed. When trying to isntall the features I get the following issue:




An error occurred while collecting items to be installed
session context was:(profile=KNIMEProfile, phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=).
Problems downloading artifact: osgi.bundle,org.lhasalimited.ceres.atomqueryextensions,
Error reading signed content:C:\Users\Samuel\AppData\Local\Temp\signatureFile6236705329733963655.jar
An error occurred while processing the signatures for the file: C:\Users\Samuel\AppData\Local\Temp\signatureFile6236705329733963655.jar
When building the site, or as a deployable feature (with manifest building) I'm not instructing to sign anything. 
All suggestions greatly appreaciated. 
Many thanks

Make sure there is no conflicting signing of jars.

When distributing your plug in, try removing from the distribution all files other than MANIFEST.MF from the Meta-Inf folder