I tried to upgrade v4.7.2 to latest version but got following msg:
An error occurred while uninstalling
session context was:(profile=profile, phase=org.eclipse.equinox.internal.p2.engine.phases.Uninstall, operand=[R]com.wireframesketcher.studio.product_root.gtk.linux.x86_64 126.96.36.19961214-1049 --> null, action=org.eclipse.equinox.internal.p2.touchpoint.natives.actions.CleanupzipAction).
Backup of file /opt/WireframeSketcher/WireframeSketcher failed.
File that was copied to backup could not be deleted: /opt/WireframeSketcher/WireframeSketcher
What method did you use to install WireframeSketcher? We supply .deb packages for Ubuntu/Debian which also registers WireframeSketcher repository. You should be able to install the new version of WireframeSketcher using system update.