ANSYS2021r1预应力模态分析报错,怎么解决啊？

 *** ERROR ***                           CP =       0.594   TIME= 10:24:29
 During the multiframe restart process, neither the .RDB file nor the   
 .Rnnn files were found.  Both files are required to perform the        
 multiframe restart for the linear perturbation analysis.  You must use 
 the RESCONTROL,LINEAR command in the prior base analysis.  The         
 ANTYPE,,RESTART command is ignored.