Piwik 1.8.2 Error

I was using Piwik for several weeks,
and now If I try to start Piwik there is this error:

There is an error. Please report the message (Piwik 1.8.2) and full backtrace in the Piwik forums (please do a Search first as it might have been reported already!).

Warning: include(HTML/QuickForm2/Element/InputText.php) [function.include]: failed to open stream: Datei oder Verzeichnis nicht gefunden in /home/a2619118/public_html/piwik/libs/HTML/QuickForm2/Loader.php on line 84

Backtrace -->
#0 Piwik_ErrorHandler(…) called at [/home/a2619118/public_html/piwik/libs/HTML/QuickForm2/Loader.php:84]#1 HTML_QuickForm2_Loader::loadClass(…) called at [/home/a2619118/public_html/piwik/libs/HTML/QuickForm2/Loader.php:84]#2 HTML_QuickForm2_Loader::loadClass(…) called at [/home/a2619118/public_html/piwik/libs/HTML/QuickForm2/Factory.php:170]#3 HTML_QuickForm2_Factory::createElement(…) called at [/home/a2619118/public_html/piwik/libs/HTML/QuickForm2/Container.php:226]#4 HTML_QuickForm2_Container->addElement(…) called at [/home/a2619118/public_html/piwik/core/QuickForm2.php:76]#5 Piwik_QuickForm2->addElement(…) called at [/home/a2619118/public_html/piwik/plugins/Login/FormLogin.php:26]#6 Piwik_Login_FormLogin->init(…) called at [/home/a2619118/public_html/piwik/core/QuickForm2.php:38]#7 Piwik_QuickForm2->__construct(…) called at [/home/a2619118/public_html/piwik/plugins/Login/FormLogin.php:21]#8 Piwik_Login_FormLogin->__construct(…) called at [/home/a2619118/public_html/piwik/plugins/Login/Controller.php:60]#9 Piwik_Login_Controller->login(…) called at [/home/a2619118/public_html/piwik/plugins/Login/Controller.php:46]#10 Piwik_Login_Controller->index(…) called at [:]#11 call_user_func_array(…) called at [/home/a2619118/public_html/piwik/core/FrontController.php:138]#12 Piwik_FrontController->dispatch(…) called at [/home/a2619118/public_html/piwik/core/Controller.php:659]#13 Piwik_Controller->redirectToIndex(…) called at [/home/a2619118/public_html/piwik/plugins/CoreHome/Controller.php:42]#14 Piwik_CoreHome_Controller->redirectToCoreHomeIndex(…) called at [:]#15 call_user_func_array(…) called at [/home/a2619118/public_html/piwik/core/FrontController.php:138]#16 Piwik_FrontController->dispatch(…) called at [/home/a2619118/public_html/piwik/index.php:53]

that’s very strange it looks like the file piwik/libs/HTML/QuickForm2/Element/InputText.php cannot be included anymore - is it there on your server ?

maybe try to reupload all files in piwik/libs/HTML ?

I reinstalled PIWIK 1.8.2 with all files,
and I got the same Error

Try to see if this file works since the error is include(HTML/QuickForm2/Element/InputText.php) [function.include]: failed to open stream

The file works and it exists,
If I call it from my browser I can open it (but it is empty)

Very strange,
A new installation in another subdir with my old config works fine again