In the ACE Model:warning messages during my data analysis

Dear developer:

When I use ACE model to calculate heritability，I got a warning messages during the analysis（See Attachment）. Is there a problem with my data and will it affect the results?
when there was a warning message, I found that the estimated results will change under different start values.

Could you please provide me more details?
Thank you very much.

Best regards,
Zhenzhen Luo