Index: branches/RC/core/install.php
===================================================================
diff -u -r11177 -r11181
--- branches/RC/core/install.php	(.../install.php)	(revision 11177)
+++ branches/RC/core/install.php	(.../install.php)	(revision 11181)
@@ -155,6 +155,7 @@
 			if (!$this->toolkit->getSystemConfig('Misc', 'WriteablePath')) {
 				// set global writable folder when such setting is missing
 				$this->toolkit->setSystemConfig('Misc', 'WriteablePath', '/system');
+				$this->toolkit->SaveConfig(); // immediately save, because this path will be used in Application later
 			}
 
 			$this->currentStep = $this->GetVar('step');
@@ -445,6 +446,7 @@
 				case 'upgrade_modules':
 					$modules = $this->Application->GetVar('modules');
 					if (!$modules) {
+						$modules = Array ();
 						$this->errorMessage = 'Please select module(-s) to ' . ($this->currentStep == 'choose_modules' ? 'install' : 'upgrade');
 					}