Cant Upload Orders To Shipping Software

Been using Shipstation for months with no problems but then last week it wouldnt download my orders

from cs-cart to shipstation

Got this error

The 'Weight' element is invalid - The value '' is invalid according to its datatype '' - The string '' is not a valid Decimal value.

Shipstation is telling me that my products need to have a weight assigned to them. I never

had weighs assigned to my products on cs-cart and software had worked well with no changes to program and now it just stopped.

I did a trial with shiprush and even though they downloaded some of my orders using that software i again see the same error there also.

If anyone can guide me to what i need to do i would appreciate it as using these shipping softwares

makes life much easier.

Thanks in advance.