Hello to everybody.
I apologize for my, for most of you, trivial question.
I am starting to use SIMATIC WinCC Basic V18 as a self-teacher.
I can do something, but now the migration of the project is bothering me.
I got help in the form of XXX.ap16.
Unfortunately, I don't know how to convert to XXX.ap18 :-(.
Can you help me or convert the file? Thank you very much

Open TIA Portal V18.
Project > Open > Browse

Select the all TIA Project extension as shown in the picture.

Navigate to the storage area where the V16 file is stored. Select and open.

Open the project as if it were a V18 project.
You will then be asked to upgrade the project.
This requires that you have TIA V16 installed.

You can install the trial version of TIA V16. Your V18 license serves as the license, as it is also valid as a license for older TIA versions.

You can download the V16 trial version from here:

SIMATIC STEP 7 inkl. Safety und WinCC V16 TRIAL Download

 After installing then the Updates.

Updates for STEP 7 V16, S7-PLCSIM V16 and WinCC V16

Thank you very much for the quick help. 
How simple :-)

Ixo, thank you. I didn't want to bother you again. 
and it also works according to qwazee

As I wrote to you, I have no V18.

That's the reason why I don't know the new function.

In TIA V16 was it so if you want to open a older projekt, then must you have older TIA version.

ixo65

As I wrote to you, I have no V18.

That's the reason why I don't know the new function.

In TIA V16 was it so if you want to open a older projekt, then must you have older TIA version.

To avoid bad understandings.. 
The capture I have shown is made from TIA Portal V15.1. Taking these steps will have the project upgraded (in this case) from WinCC V16 to WinCC V18. To be able to edit V16 and remain with V16 will need the install of V16, as Mr. ixo65 suggests. It is possible to have V16 installed and operational with the V18 license.

See attachment.

So shows TIA V16 if I want to open a V14 projekt.