4S cannot complete your iTunes store request 50

Because the itunesprefs. xml file also contains parameters including the EQ balancer settings, you can follow the steps below to solve this problem while maintaining these EQ settings. (Note: Exit iTunes before performing the following operations)
1) follow the steps in method 1 to enter the % USERPROFILE % \ Application Data \ Apple Computer \ iTunes directory and find itunesprefs. open the XML file in the XML editor. (Note: Do not open the file in notepad or WordPad that comes with windows. Otherwise
Itunesprefs. xml Encoding Error, causing iTunes to fail to read and recreate the file ).
Notepad ++ is recommended. After notepad ++ is installed, start notepad ++ and drag the itunesprefs. xml file to the notepad ++ main interface to open it.
2) drag the scroll bar to the bottom of the itunesprefs. xml file. The following fields are displayed:
Storefront
143465-
Change the parameters in string to the following:
Storefront
143465-
Save, disable notepad ++, and restart iTunes.