Fatal error on query (no replies)

Hi there, maybe the problem is just stupid, but still i need a help...

I have MySQL installed (don't know what version) installed on a Intel i5 with 8 GB of RAM, with XAMPP control panel 3.2.2 and I use the MySQL Connector with VB.NET to make applications and share the databases with PHP for web. My problem is, every time I create a query that is different from all others before that one, and I run in on any software created in VB.NET i got a "Fatal Error" while running! But, if I run the same query before or after any test on VB.NET in PHPMyAdmin, and the query is OK and don't have errors, and return what is expected, if I run the VB.NET program again, it runs with no error at all... is there any explanation for that? any way to solve this?

thanks in advance!