Overview:
An error occurs when a user is not able to create any new dynamic dashboard: You reached the limit for Dashboards run as the logged-in user.
Root Cause:
This organization is an Unlimited Edition organization. It can have a maximum of 10 Dynamic Dashboards. As of now, there are 10 Dynamic Dashboards created and as such, the user is not able to save another one.
Solution:
Consider increasing the number of Dynamic Dashboards. Note: There is an additional cost to do so.
Or, clear the Recycle bin for the deleted Dashboards. After this is done, the user should be able to create a new Dynamic Dashboard.
Related Documentation:
Thank you