Al Pascual ASP.NET Blog

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

Thats what happens when you call a public method of an ajax API with the incorrect number of parameters. For example, try Boolean.parse("true", "what?"). It only takes 1 parameter, you passed in 2. This error is only thrown in debug mode, which is probably why you dont get it if you dont use the script manager (you're using the release mode of the script when you reference it manually, arent you?)

You aren't finding many specific articles about the error because it's such a generic error -- thousands of methods can throw this error.

As for what method it is you are calling, the best way to find out is to look at the call stack when the exception occurs.

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

The most likely reason is that one of the values you are submitting is null or undefined. This will cause the javascript proxy function to completely drop the parameter. So instead of having x name/value pairs, one which contains a null, you have only the name/value pairs of non-null values.

The easies way to debug this is through Firebug or with Fiddler2.

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

Agreed With Sean.

One or more parameter may have empty name/value pair.

U have debug it using FireBug or fiddler

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

I set the ScriptMode property to Release for the ScriptManager control, and the problem got solved.

Refer: www.asp.net/.../ASPNETAJAXDebuggingAndTracingOverview.aspx

Thanks.

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

Who on earth would go to cuil.com to search for an error message, obviously you are trying to get them some links.

Epic fail.

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

What the ajax sys parametercountexception parameter count mismatch error.. Ho-o-o-o-t :)

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

What the ajax sys parametercountexception parameter count mismatch error.. Great! :)

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

What the ajax sys parametercountexception parameter count mismatch error.. Outstanding :)

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

I discovered in my striving to fix this issue that another cause can be attempting to send an array of different types. In my case, I had 1 int and some others that had been cast as decimals. When the compiler attempted to send this, it couldn't convert the remaining pairs to strings and errored out.

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

I was getting this error and was able to fix the problem.

It took me a long time to figure out.

I was coding dsOutParams.addParameter with SqlDbType.Bit.ToString, length = 1

for a bit db field.

I changed this to

SqlDbType.Int.ToString, length = 4

and the error went away.

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

thanks, Valliappan. I got my problem solved by following your suggestion

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

Oh Yes! Thankyou. I had this error when I upgraded from VS2008 to 2010 and moved to Win 7 at the same time. All was working OK before, but after the upgrade I got this error more or less every time I launched a page from my main menu page. Sometimes it would launch OK the first time then give the error the next time.

Setting the ScriptManager scriptmode to 'release' appears to have solved it :)

Thanks again!

# re: What the AJAX Sys.ParameterCountException: Parameter count mismatch error?

Setting the ScriptManager scriptmode to 'release' worked for me too.

It seems to be best way out