Operation is not valid due to the current state of the object

One of our developers intermittently gets this error "Operation is not valid
due to the current state of the object" when exporting a report to Excel from
Preview in Designer. It seems to happen when he attempts to export a second
time after changing a parameter value in Preview. Any thoughts?I'm getting the same error, only it doesn't happen in Report Designer, only
when viewing it on the web using the ReportServer. Very strange... And only
with certain parameters.
"toolman_2000" wrote:
> One of our developers intermittently gets this error "Operation is not valid
> due to the current state of the object" when exporting a report to Excel from
> Preview in Designer. It seems to happen when he attempts to export a second
> time after changing a parameter value in Preview. Any thoughts?