The exact error message is...
com.sun.org.apache.xerces.internal.impl.io.MalformedByteSequenceException: Invalid byte 1 of 1-byte UTF-8 sequence.
Plugin: org.eclipse.equinox.p2.updatesite 1.0.500.v20150423-1455
Message: Error reading update site http://mercurialeclipse.eclipselabs.org.codespot.com/hg.wiki/update_site/stable.
I get the same error message on both version 2.1 and 1.8 via the Eclipse MarketPlace.
If I install another plugin like "EMMA", that works fine.
If I select "Help" > "Check for updates", I get the same error message.
Can anyone suggest a fix/workaround ?
NOTES:
Installing via the update URL works (SNAPSHOT ONLY, not RELEASE)
http://mercurialeclipse.eclipselabs.org.codespot.com/hg.wiki/update_site/snapshots