Eclipse revert old version Android Development Tools

Invalid proguard configuration file path
C:\documents\my_android_projects\my_project\proguard.cfg does not exist or is not a regular file

Solution:
Check if exist file proguard.cfg in your project on the path C:\docum.........
If not exist, copy a file proguard.cfg from other project or create file proguard.cfg and insert
this source code to file and save this file.

-optimizationpasses 5
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService

-keepclasseswithmembernames class * {
    native <methods>;
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet);
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers class * extends android.app.Activity {
   public void *(android.view.View);
}

-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

From more details see:
//developer.android.com/guide/developing/tools/proguard.html

Incorrect line ending: found carriage return (\r) without corresponding newline (
)

Move mouse cursor on error text and press Ctrl+1
Select Fix line endings and press Enter

See image below:

If you using Context as parameter of function try this solution:

public class MyActivity extends Activity {
// bla bla bla .......
//error 
myFc( getapplicationcontext());
// OK
myFc(MyActivity.this);

For some graphics you can use Paint.NET editor.
//www.getpaint.net/
How create Snow Effects on Text by 1 minute show this video:

Physical pixel (px)
Density independent pixel (dp)
Dots per inch (dpi) .. physical pixels per inch
px = dp * (dpi / 160)

public static int dpToPx(int dp)
{
    return (int) (dp * Resources.getSystem().getDisplayMetrics().density);
}

public static int pxToDp(int px)
{
    return (int) (px / Resources.getSystem().getDisplayMetrics().density);
}