Random Effects probit model - industry and time dummies

#1
Hi everyone,

I'm runnig this model in STATA, in a panel database of firms. As the dependent variable is a binary one, I use: xtprobit Y x1 x2 x3, re.

I have these questions:

1) Should I also include industry and time fixed effects? (i.e. i.industry, i.year)
2) When I try to include vce(robust), I get an error message: "calculation of robust standard errors failed". How can I fix it?

Many thanks for your help.