Sys.WebForms.PageRequestManagerServerErrorException: Input string was not in a correct format.

Hi i am getting js runtime error

my page has update panel and on dropdown selected change page get refresh..

but for one selection i am getting this error

Sys.WebForms.PageRequestManagerServerErrorException: Input string was not in a correct format.

http://localhost/ScriptResource.axd?d=RiFuCSbdE4G_ab3bMy_quisiB0USwZ0HzD18y9i-HlhJgwjDta0nI56grwpM8wxT1PmOFvKVlkDzhHWroUPogswnOoNCNvywwF7W541r-fo1&t=8153c76

ScriptResource.axd is a file dynamically genrated by resource manager so using firbug and idev tool i tried to debug but couldn't..

Thanks in advance

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