Trouble starting Bizagi Studio - Input string was not in a correct format

I have installed Bizagi Studio - using an existing previous SQL Express - and have this error when trying to launch it System.FormatException: Input string was not in a correct format. at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal) at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info) at System.Int16.Parse(String s, NumberStyles style, NumberFormatInfo info) at System.Convert.ToInt16(String value) at BizAgiStudio.Program.BizagiStudioOpenCount() at BizAgiStudio.Program.VerifyRegistration() at BizAgiStudio.Program.RunBizAgi() at BizAgiStudio.Program.Main(String[] Args)