Value was either too large or too small for an Int16 after many years
<p>One of my application is running since 2005. Now it gives error mentioned below.</p>

<p>I don't know what happened. Did any one face any issue like this?</p>

<pre><code>Server Error in '/' Application.
Value was either too large or too small for an Int16.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 
Exception Details: System.Exception: Value was either too large or too small for an Int16.
Source Error: 
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Stack Trace: 
[Exception: Value was either too large or too small for an Int16.]
   Attach_DL.Generatekey() +121
   Attach_BL.GenerateKey() +12
   Picture.AddAttachments(String _attachpath, String _attachpathDB) +289
   Picture.Btnsave_Click(Object sender, EventArgs e) +1416
   System.Web.UI.WebControls.Button.OnClick(EventArgs e) +111
   System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +110
   System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565
Version Information: Microsoft .NET Framework Version:2.0.50727.4927; ASP.NET Version:2.0.50727.4927
</code></pre>