#167 I first Assign an approval workflow get some error

app/models/dmsf_lock.rb

@@ -47,7 +47,7 @@ class DmsfLock < ActiveRecord::Base
   end
 
   def generate_uuid
-    self.uuid = UUIDTools::UUID.timestamp_create().to_s
+    self.uuid = UUIDTools::UUID.random_create.to_s
   end
 
   def self.delete_expired

db/migrate/07_dmsf_1_4_4.rb

@@ -60,7 +60,7 @@ class Dmsf144 < ActiveRecord::Migration
     do_not_delete.each {|l|
       #Find the lock
       next unless lock = DmsfFileLock.find(l)
-      lock.uuid = UUIDTools::UUID.timestamp_create().to_s
+      lock.uuid = UUIDTools::UUID.random_create.to_s
       lock.save!
     }