Ubuntu Redmine uninstallation problem

While uninstalling redmine from Ubuntu faced following problem that

cat: /etc/redmine/.instances: No such file or directory
dpkg: error processing package redmine (--remove):
   Installed redmine package post-removal script subprocess returned error exit status 1

This creates problem and will not solve even if you try
#dpkg --configure -a
#apt-get autoclean
#apt-get remove redmine --purge

To solve this problem

Step 1
Open
#vim /var/lib/dpkg/info/redmine.postrm

Step 2
And comment out the lines which perform this check

....
....
instances=$(cat /etc/redmine/.instances)
for inst in ...
   ...
   ...
done

Step 3
Run command to remove redmine.