General Description: During Place and Route, the following warning appears:
Warning: basrt:188 routing for this placement cannot meet all timing constraints. It may have as many as 1 timing errors.
Near the beginning of Place and Route, this feature tells the user that the timing constraints will probably not be met.
This message is an indication that the router is very likely to not meet all timing constraints with the current placement. To correct this problem, rerun PAR at the highest effort level (-ol 5) and try multiple placement seeds (-n #) to try to find a placement that will meet timing.
If this more in-depth PAR strategy is not successful, it will be necessary to use timing analysis to examine the failing paths. You may then want to consider floorplanning the design, or modifying the design to reduce the number of logic levels.