Step 1: In Power BI Desktop, Go to File menu and select Options and Settings > Option
Step 2: Click on Data Load Button.
Step 3: Next click on "Clear Cache" button under both "Data Cache Management Options" and "Q&A Cache Options". Press OK.
Step 4: Once cleared both caches, make sure the "Currently used" value is 0 bytes like the below screenshot.
To clear the Data Source Settings Cache:
Step 1: In Power BI Desktop, Go to the File menu and select Options and Settings > Data Source settings
Step 2: On the "Data Source settings" window, choose the "BI Connector" data sources in the list displayed and select "Clear Permissions". This will clear the credentials cache for the particular data source.
Alternatively, you can clear the credentials cache for all the saved data sources by clicking on the "Clear All Permissions" option. This will clear the credentials information for all the saved data sources.
Relaunch Power BI Desktop:
After clearing cache and data source settings, make sure sure to close all the instances of Power BI desktop.
Now relaunch the Power BI desktop and try working with subject area (or reports).