GP Card Manager Failed

[filip1101]

I try to install, download, and select and applet on pyAPDU Tool. I tried different applets so i don't think the problem is in the applet. When i try to download .cap file i get this error:
Download Cap error: Select GP Card Manager failed. Send: 00 A4 04 00 00, Recv: 00 00.
, when i try to install an applet i get this error:
Install Applet error: GP init update failed. recv: 00 00
And when i try to select the applet it gives me this error:
Select Applet error: global name 'util' is not defined.
I use ISO14443A MIFARE 1k Tag and
ACS ACR122u Reader
Is something wrong with the card or the reader or it is something else.
I need this fast so if you can tell me

[bigWhite]

If you fail to download the CAP, the install and select applet will definitely be failed.
Select GP Card Manager failed, it may be that the card's GP key has been modified, not the default 0x40-0x4F

[filip1101]

What do you mean that the GP Key has been modified? And how to change it?

[filip1101]

What do you mean that the Gp Key is modified? Do you know how can I change it?