Warning (15714): Some pins have incomplete I/O assignments. Refer to the I/O Assignment Warnings report for details
警告（15714）：某些管脚的I/O分配不完整。有关详细信息，请参阅I/O分配警告报告
The incomplete I/O warnings are not listed with the other warnings. You manually need to go into the fitter report and select "I/O Assignment Warnings report". You should then see the list of missing assignments.
需要规定信号强度，In the pin planner in the pin list there's a column called Current Strength.
If it doesn't show up there, right-click your mouse in the pin list and select customize columns.... You can add the currenth strenght column and select the desired drive strength.
找到相应管脚，然后到下面界面设置