asp.net - how to resolve this error in paypal sandbox -

paypal payment standard method(sandbox),

after doing setup in buyer account,

when transaction time need retrieve payment status(success/failure), of these options, payment status.

1) instant payment notification (ipn)

2) payment data transfer(pdt)

when enable payment data transfer(pdt) on.

while doing transaction in paypal receive these error this...

rapids::exception (n6rapids5tools13pimpexceptione): pimp rc: 3514

failure log: use of pimp_rc (4814), use of pimp_rc (3013), use of pimp_rc (4814), use of pimp_rc (3174), use of pimp_rc (14816), use of pimp_rc (9449), use of pimp_rc (9445), use of pimp_rc (4814), use of pimp_rc (3507), use of pimp_rc (4001), use of pimp_rc (4002), use of pimp_rc (3778), use of pimp_rc (4007), use of pimp_rc (4020), use of pimp_rc (7003), use of pimp_rc (3583), use of pimp_rc (3051), use of pimp_rc (3001), use of pimp_rc (3021), use of pimp_rc (3242), use of pimp_rc (3165), use of pimp_rc (3101), use of pimp_rc (3085), use of pimp_rc (3209), use of pimp_rc (3174), use of pimp_rc (3043), use of pimp_rc (3241), use of pimp_rc (3082), use of pimp_rc (3129), use of pimp_rc (3567), use of pimp_rc (3235), use of pimp_rc (3236), use of pimp_rc (3508), use of pimp_rc (3507), use of pimp_rc (3531), use of pimp_rc (3514), use of pimp_rc (3124), use of pimp_rc (3047), use of pimp_rc (3224), use of pimp_rc (3093), use of pimp_rc (3253), use of pimp_rc (3254), use of pimp_rc (3083), use of pimp_rc (3137), use of pimp_rc (3256), use of pimp_rc (14268), use of pimp_rc (14267), use of pimp_rc (14266), use of pimp_rc (14269), use of pimp_rc (14264), use of pimp_rc (14265), use of pimp_rc (14244), use of pimp_rc (3084), use of pimp_rc (3254), use of pimp_rc (3083), use of pimp_rc (3137), use of pimp_rc (3070), use of pimp_rc (3141), use of pimp_rc (3198), use of pimp_rc (3011), use of pimp_rc (10021), use of pimp_rc (3199), use of pimp_rc (3015), use of pimp_rc (3014), use of pimp_rc (3200), use of pimp_rc (3257), use of pimp_rc (3012), use of pimp_rc (3141), use of pimp_rc (3535), use of pimp_rc (3504), use of pimp_rc (10022), use of pimp_rc (6702), use of pimp_rc (3001), use of pimp_rc (3120), use of pimp_rc (3517), use of pimp_rc (3531), use of pimp_rc (3201), use of pimp_rc (3803), use of pimp_rc (6834), use of pimp_rc (3807), use of pimp_rc (3808), use of pimp_rc (3810), use of pimp_rc (3812), use of pimp_rc (3809), use of pimp_rc (3805), use of pimp_rc (2002), use of pimp_rc (3177), use of pimp_rc (3051), use of pimp_rc (3510), use of pimp_rc (4003), use of pimp_rc (3013), use of pimp_rc (4011), use of pimp_rc (3300), use of pimp_rc (3286), use of pimp_rc (6681), use of pimp_rc (14605), use of pimp_rc (10361), use of pimp_rc (14353), use of pimp_rc (14817), use of pimp_rc (4002), use of pimp_rc (2001), use of pimp_rc (4001), use of pimp_rc (11045), use of pimp_rc (3593), use of pimp_rc (4071), use of pimp_rc (3514), use of pimp_rc (4022), (rcf @ virtual int merchant::pimpautosellerbliimpl::seller_generate_transaction_token(ullong, pimptransid&):406) , use of pimp_rc (3514) backtrace: ppexception::ppexception(string const&) rapids::tools::pimpexception::pimpexception() rapids::businessblocks::hostedpayments::get_synch_ipn_url(paypalcommonwebappcontext const&, unsigned long long, string const&, string const&, string&, pimptransaction const&, miscubiquitycontainer&, transactionubiquitycontainer&, string const&, unsigned long long) rapids::businessblocks::hostedpayments::get_synch_ipn_url(paypalcommonwebappcontext const&, pimpxclick&, pimptransaction const&, miscubiquitycontainer&, transactionubiquitycontainer&, unsigned long long) rapids::flows::hostedpayments::stateautoreturncheck::execute(rapids::cgivars const&) rapids::decoratedstate::execute(rapids::cgivars const&) riprap::ripraprapidsgenericflow::handle_execute(riprap::webappcontextornate const&, rapids::transitionregistry const&, rapids::state*, string const&, string const&, unsigned long long) riprap::ripraprapidsgenericflow::process_states(riprap::webappcontextornate const&, riprap::ripraprapidsgenericflow::processstates, riprap::dispatchinterceptorregistry const&, rapids::transitionedge const*) riprap::ripraprapidsgenericflow::flow_continue_from_interception(riprap::webappcontextornate const&, riprap::webappreturn const&, riprap::dispatchinterceptorregistry const&) riprap::call_rapids(riprap::webappcontext const&, riprap::rapidsflowfactory const&, riprap::dispatchaction const&, riprap::webappreturn const&, string const&, riprap::dispatchinterceptorregistry const&) riprap::dispatch_loop(riprap::epregistry const&, riprap::webappcontext const&, riprap::dispatchaction&, riprap::webappreturn&, string const&, riprap::dispatchinterceptorregistry const&) riprap::dispatch_wrapper(outputstream&, riprap::epregistry const&, riprap::webappcontext const&, riprap::webappreturn const&, string const&, bool const&, riprap::dispatchinterceptorregistry const&) riprap::entry_point(httpinterface&, riprap::cgivars&, outputstream&, string const&, string const&) main  error has occurred.  return homepage