Want to share this scenario:
I started getting this error message when running SSRS report in one of the environment and I was bit surprised that why suddenly I face this error although I was able to run the reports properly 5 minutes back:
As I was attached to system administer role so I was pretty sure that it was not a security permission issue inside AX. Google search resulting in several links and one of them suggested to log off from the windows and log back in.
On doing that system prompted me that my domain password has expired and must be changed. So I changed the password and then when I ran the report in AX again it executed successfully.
So in this case, the domain password was expired which resulted in SSSR report execution error.
This might not be a sure shot solution but it worked for me.In case you have also faces similar issue then please do comment on the resolution you found for this.
Have a good day.