The version of Quartus II being used indicates that the timing characteristics of the selected device are preliminary and may change in the future.

To avoid this,
Use a version of Quartus II whose timing model has been verified.
⇒ If you are using the latest released version, the timing characteristics to be released in the future have been fixed.
Please wait for Version
・ Change the selected device to a device with fixed timing characteristics
becomes.

The following shows how to check the version of Quartus II being used and whether there is a service pack.
・ Select Help ⇒ About Quartus II from the Quartus II toolbar.

Please refer to the “Timing and Power Models” section in the Device Support Release Notes at the URL link below for the timing characteristics of each device and size.
■ Latest Device Support Release Notes
       https://www.altera.com/en_US/pdfs/literature/rn/rn_qts_dev_support.pdf
■ Old version Device Support Release Notes
       https://www.altera.com/support/literature/archive-listing-4-gsa.html