diff --git a/Gemfile.lock b/Gemfile.lock
index 28c3300..353a30d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,8 +1,8 @@
 PATH
   remote: .
   specs:
-    ZCRMSDK (0.1.0)
-      json (~> 1.8)
+    ZCRMSDK (1.0.1)
+      json (~> 2.2)
       multipart-post (~> 2.0)
       rest-client (~> 2.0)
 
@@ -10,18 +10,21 @@ GEM
   remote: https://rubygems.org/
   specs:
     diff-lcs (1.3)
-    domain_name (0.5.20180417)
+    domain_name (0.5.20190701)
       unf (>= 0.0.5, < 1.0.0)
+    http-accept (1.7.0)
     http-cookie (1.0.3)
       domain_name (~> 0.5)
-    json (1.8.3.1)
-    mime-types (3.2.2)
+    json (2.2.0)
+    mime-types (3.3)
       mime-types-data (~> 3.2015)
-    mime-types-data (3.2019.0331)
+    mime-types-data (3.2019.1009)
     multipart-post (2.1.1)
+    mysql2 (0.5.2)
     netrc (0.11.0)
     rake (10.5.0)
-    rest-client (2.0.2)
+    rest-client (2.1.0)
+      http-accept (>= 1.7.0, < 2.0)
       http-cookie (>= 1.0.2, < 2.0)
       mime-types (>= 1.16, < 4.0)
       netrc (~> 0.8)
@@ -48,6 +51,7 @@ PLATFORMS
 DEPENDENCIES
   ZCRMSDK!
   bundler (~> 2.0)
+  mysql2 (~> 0.5.2)
   rake (~> 10.0)
   rspec (~> 3.0)
 
diff --git a/ZCRMSDK.gemspec b/ZCRMSDK.gemspec
index cb74f3c..2a6258f 100644
--- a/ZCRMSDK.gemspec
+++ b/ZCRMSDK.gemspec
@@ -21,7 +21,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'bundler', '~> 2.0'
   spec.add_runtime_dependency 'multipart-post', '~> 2.0'
   spec.add_runtime_dependency 'rest-client', '~> 2.0'
-  spec.add_runtime_dependency 'json', '~> 1.8'
+  spec.add_runtime_dependency 'json', '~> 2.2'
   spec.add_development_dependency 'rake', '~> 10.0'
   spec.add_development_dependency 'rspec', '~> 3.0'
   spec.add_development_dependency 'mysql2', '~> 0.5.2'
diff --git a/lib/ZCRMSDK/persistence.rb b/lib/ZCRMSDK/persistence.rb
index d07717d..70b3dba 100644
--- a/lib/ZCRMSDK/persistence.rb
+++ b/lib/ZCRMSDK/persistence.rb
@@ -72,8 +72,9 @@ def save_oauth_tokens(oauth_tokens)
         file_obj.close
         arr = Marshal.load(serialized) unless serialized.nil? || serialized.empty?
         arr.push(oauth_tokens)
-        file_obj = File.open(path, 'w+')
-        file_obj.write(Marshal.dump(arr))
+        marshalled_tokens = Marshal.dump(arr)
+        file_obj = File.open(path, "w:#{marshalled_tokens.encoding.to_s}")
+        file_obj.write(marshalled_tokens)
         file_obj.close
       end
 
diff --git a/lib/ZCRMSDK/utility.rb b/lib/ZCRMSDK/utility.rb
index 612d897..5e265de 100644
--- a/lib/ZCRMSDK/utility.rb
+++ b/lib/ZCRMSDK/utility.rb
@@ -304,6 +304,13 @@ def initialize(url, status_code, err_message, exception_code = 'error', details
       def self.get_instance(url, status_code, err_message, exception_code = 'error', details = nil, content = nil)
         ZCRMException.new(url, status_code, err_message, exception_code, details, content)
       end
+
+      def to_s
+        "#{self.class}\n#{exception.url}\n#{exception.status_code}"\
+        "- #{exception.error_message}\n"\
+        "#{exception.exception_code}\n#{error_details}\n#{error_content}"
+      end
+
     end
   end
 end
diff --git a/lib/ZCRMSDK/version.rb b/lib/ZCRMSDK/version.rb
index f2c1ca5..dc57155 100644
--- a/lib/ZCRMSDK/version.rb
+++ b/lib/ZCRMSDK/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module ZCRMSDK
-  VERSION = '1.0.0'
+  VERSION = '1.0.2'
 end