I have a dashboard with 50 datasets, I want to import more, but the add dataset button appears disabled, I have already tried in other dashboards and let me import, what would be the solution or if the maximum dataset to import is 50?
Yes. The max number of datasets that can be used in a dashboard is 50.
Please explore option of consolidating your data into smaller number of datasets - either in ETL layer or through use of custom SQL option.