1-Click upgrade 1.6.1.20 to 1.7.4.2 NOT working

[seanr22a]

I'm running 1.6.1.20  and wanted to give the latest 1-Click Upgrade (downloaded today) a try upgrading to 1.7.4.2 but it's not working. Anyone managed to get it working ?

This is the error:

All files upgraded. Now upgrading database...
[Ajax / Server Error for action upgradeDb] textStatus: "error " errorThrown:" " jqXHR: "
[PrestaShopException]
[ThemeRepository] Theme configuration file not found for theme at
`/volume1/web/prestashop/themes/classic/config/theme.yml`.
at line 132 in file src/Core/Addon/Theme/ThemeRepository.php
127. }
128.
129. private function getConfigFromFile($file)
130. {
131. if (!$this->filesystem->exists($file)) {
132. throw new PrestaShopException(sprintf(
133. '[ThemeRepository] Theme configuration file not found for theme at
`%s`.',
134. $file
135. ));
136. }
137.
 PrestaShop\PrestaShop\Core\Addon\Theme\ThemeRepository-
>getConfigFromFile - [line 65 -
src/Core/Addon/Theme/ThemeRepository.php] - [1 Arguments]
 PrestaShop\PrestaShop\Core\Addon\Theme\ThemeRepository-
>getInstanceByName - [line 491 - classes/shop/Shop.php] - [1 Arguments]
 ShopCore->setTheme - [line 135 - classes/shop/Shop.php]
 ShopCore->__construct - [line 411 - classes/shop/Shop.php] - [1
Arguments]
 ShopCore::initialize - [line 119 - config/config.inc.php]
 require_once - [line 475 -
modules/autoupgrade/classes/UpgradeContainer.php] - [1 Arguments]
 PrestaShop\Module\AutoUpgrade\UpgradeContainer-
>initPrestaShopCore - [line 120 -
modules/autoupgrade/classes/TaskRunner/AbstractTask.php]
 PrestaShop\Module\AutoUpgrade\TaskRunner\AbstractTask-
>init - [line 73 -
modules/autoupgrade/classes/TaskRunner/Upgrade/UpgradeDb.php]
 PrestaShop\Module\AutoUpgrade\TaskRunner\Upgrade\UpgradeDb-
>init - [line 51 - admin/autoupgrade/ajax-upgradetab.php]
"

1-click_failure_1.6-20_to_1.7.4.2.pdf