TYPO3 Core

After disabling versioning I got the following error message in 8.7.0 that wasn't there in 8.6.1 and cannot be resolved by clearing the cache:

Uncaught TYPO3 Exception
strlen() expects parameter 1 to be string, null given

TypeError thrown in file
/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/frontend/Classes/Typolink/PageLinkBuilder.php in line 202.

11 strlen(NULL)

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/frontend/Classes/Typolink/PageLinkBuilder.php:

00200:                     // domains. absRefPrefix can contain domain name, which will screw up
00201:                     // the link to the external domain.

00202:                     $prefixLength = strlen($tsfe->config['config']['absRefPrefix']);

00203:                     if (substr($LD['totalURL'], 0, $prefixLength) === $tsfe->config['config']['absRefPrefix']) {
00204:                         $LD['totalURL'] = substr($LD['totalURL'], $prefixLength);

10 TYPO3\CMS\Frontend\Typolink\PageLinkBuilder::build(array, "|", "", array)

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/frontend/Classes/ContentObject/ContentObjectRenderer.php:

05610:             );
05611:             try {

05612:                 list($this->lastTypoLinkUrl, $linkText, $target) = $linkBuilder->build($linkDetails, $linkText, $target, $conf);

05613:             } catch (UnableToLinkException $e) {
05614:                 // Only return the link text directly

9 TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer::typoLink("|", array)

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/frontend/Classes/ContentObject/ContentObjectRenderer.php:

05749:     public function typoLink_URL($conf)
05750:     {

05751:         $this->typoLink('|', $conf);

05752:         return $this->lastTypoLinkUrl;
05753:     }

8 TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer::typoLink_URL(array)

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/frontend/Classes/Controller/TypoScriptFrontendController.php:

02915:             $parameter .= ',' . $type;
02916:         }

02917:         $redirectUrl = $cObj->typoLink_URL(['parameter' => $parameter, 'addQueryString' => true,

02918:             'addQueryString.' => ['exclude' => 'id']]);
02919: 

7 TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController::redirectToCurrentPage()

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/frontend/Classes/Controller/TypoScriptFrontendController.php:

02896:     {
02897:         if (!empty($this->originalShortcutPage) && $this->originalShortcutPage['doktype'] == PageRepository::DOKTYPE_SHORTCUT) {

02898:             $this->redirectToCurrentPage();

02899:         }
02900:     }

6 TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController::checkPageForShortcutRedirect()

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/frontend/Classes/Http/RequestHandler.php:

00193: 
00194:         // Check for shortcut page and redirect

00195:         $this->controller->checkPageForShortcutRedirect();

00196:         $this->controller->checkPageForMountpointRedirect();
00197: 

5 TYPO3\CMS\Frontend\Http\RequestHandler::handleRequest(TYPO3\CMS\Core\Http\ServerRequest)

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/core/Classes/Core/Bootstrap.php:

00308: 
00309:         // Execute the command which returns a Response object or NULL

00310:         $this->response = $requestHandler->handleRequest($request);

00311:         return $this;
00312:     }

4 TYPO3\CMS\Core\Core\Bootstrap::handleRequest(TYPO3\CMS\Core\Http\ServerRequest)

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/frontend/Classes/Http/Application.php:

00077:     public function run(callable $execute = null)
00078:     {

00079:         $this->bootstrap->handleRequest(\TYPO3\CMS\Core\Http\ServerRequestFactory::fromGlobals());

00080: 
00081:         if ($execute !== null) {

3 TYPO3\CMS\Frontend\Http\Application::run()

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/frontend/Resources/Private/Php/frontend.php:

00021: call_user_func(function () {
00022:     $classLoader = require __DIR__ . '/../../../../../../vendor/autoload.php';

00023:     (new \TYPO3\CMS\Frontend\Http\Application($classLoader))->run();

00024: });

2 {closure}()

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typo3/sysext/frontend/Resources/Private/Php/frontend.php:

00022:     $classLoader = require __DIR__ . '/../../../../../../vendor/autoload.php';
00023:     (new \TYPO3\CMS\Frontend\Http\Application($classLoader))->run();

00024: });

1 require("/homepages/30/d67027059/htdocs/typo3_src-8.7.0/typ…sysext/frontend/Resources/Private/Php/frontend.php")

/homepages/30/d67027059/htdocs/typo3_src-8.7.0/index.php:

00001: <?php
00002: 

00003: require __DIR__ . '/typo3/sysext/frontend/Resources/Private/Php/frontend.php';

All migration assistants and the backend work fine.