I am doing geometry optimization using Dmol3. It works fine without asking any property. Then i put "Use_DIIS_Restart off "to calculate the frequency in the input file. For some case it works fine, but in some cases i get the following error.

Error: DMol3 exiting

Error: opening SYM file

Error: opening SYM file                                    

Error: opening SYM file                                    

Error: opening SYM file                                    

Error: opening SYM file                                    

Error: opening SYM file                                    

Error: opening SYM file