problems after upgrade to mdk 4.10

I really doubt that's necessary - possibly not even helpful.

It looks very much like a simple matter of the Project include paths being wrong:

error: #5: cannot open source input file "stdio.h": No such file or directory

Have you checked that "stdio.h" does, in fact, exist on your PC?

If it does, have you checked that your project is correctly configured to find it?

I really doubt that's necessary - possibly not even helpful.

It looks very much like a simple matter of the Project include paths being wrong:

error: #5: cannot open source input file "stdio.h": No such file or directory

Have you checked that "stdio.h" does, in fact, exist on your PC?

If it does, have you checked that your project is correctly configured to find it?

We had a similar issue with a TCPNet header file. We had to include the right path in the file properties (options for file...) to make it work. I think it has something to do with having installed more than one MDK version in different paths, but I'm not sure.

Yes, of course - you always have to specify the right path somehow!

There are many ways to do it; eg,

* In the Project properties - to apply to the whole Project;

* In the Group properties - to apply to the whole Group;

* In the File properties - to apply to an individual file.

You can, of course, even put a fully-qualified path in the source code; eg,

#include "C:/blah//Keil/blah/blah/includes/stuff.h"

And if you don't specify explicitly somehow in your Project and/or source, then the tools will use some default, which may or may not be what you need - especially if you've been installing and/or updating multiple versions...

Getting the include paths right is a standard part of any porting exercise - including an update of the tool versions.

Yes, but the strange thing was that as far as I could tell, the file was located at the right place (but still it was required to specify an explicit location). Personally I never had such issues, as I always install MDK update on top of each other (thus, into the same root path).