SQL Server deprecated Functions effect I'm using SQL Server in various versions. In case of this I'm using functions which got deprecated. 

My question is, how a deprecated function affects the usage of SQL Server?

The functions are still working but could it be, that any settings blocking the execution?

Thanks for your help.
Deprecated functions / features work fine in your current SQL Server Version. It is just a hint for you that in future versions of the SQL Server these functions will be dissmissed or replaced by others.
It doesn't mean that these functions are removed in the very next version, but it is planned in long term to remove them.

A list of deprecated features is available here: Microsoft SQL Server 2016 Deprecated features