A workbook cannot contain more than 1000 requests. If you have reports or projects that require more than 1000 data requests, Adobe recommends separating them into multiple workbooks.
Report Builder uses the Analytics API to retrieve data, which is limited to 20,000 requests per hour across your entire login company. API requests include any time data is retrieved or refreshed. If you hit this hourly limit, wait until the next hour to retrieve data again. Each data request in a workbook counts as an API call whenever it is created or refreshed.
Scheduled reports time out after processing past 4 hours. If your workbook contains many complex requests using large data sets, the scheduled report can fail.