What utility are you using to upload with?  Are you using the namespace?  By default, objects created are given the ACL (creator)=FULL_CONTROL and nothing else.  This also applies to any directories created implicitly or otherwise.  So, if another token created the object and/or directories, you won't have access to them unless you change the ACL.

I'm using Java api.

Yes, I'm using namespace.

Sorry, but in that case how other user can upload or download files using his own tokens.

Thanks a lot.

If you wish to share data between tokens, you should either add public access to the object's ACL and/or the other UIDs.  For example, when you create an object, you can set the public read ACL like this:

              ObjectPath path = new ObjectPath("/path/to/file.txt");

        Acl acl = new Acl();

        acl.addGrant( new Grant( new Grantee( uid, Grantee.GRANT_TYPE.USER ), Permission.FULL_CONTROL ) );

        acl.addGrant( new Grant( Grantee.OTHER, Permission.READ ) );

        ObjectId id = this.esu.createObjectOnPath(path, acl, null, null, "text/plain" );

Note that "uid" above is the last part of your token.  If your token is abcd123.../test2, "uid" should only be "test2".  In the above example, you will also need to either manually create the directories /path/ and /path/to/ or update their ACL after creating /path/to/file.txt.