Use SOAP Web Service to create quote issue.

I have a integration service do so a series integration. If there is any error, when create quote SQH, it will give error:

@X3.TRT/SUBSFIT$adx (149) Error 7 : Class Non-existent [M:SFIT]

0 : Sage X3 errors

After restart the X3 SOAP Web Service then it works and without error.

Please help.