Error after update from 0.6.1 to 0.9.1

[dreizehnb]

Baikal version: 0.9.1

• I have searched open and closed issues for duplicates
• I have installed the release zip, not the source code zip
• I have moved the whole, untouched Specific and config folders to the new installation

Problem:
Hi,
after updating my PHP-Version to 7.4 and uploading the the folders from the zip-FIle to my domain, I get the following error:
Error: Class 'Twig\Cache\NullCache' not found in /homepages/17/XXX/htdocs/dav/baikal/vendor/twig/twig/src/Environment.php:270
Stack trace:
#0 /homepages/17/XXX/htdocs/dav/baikal/vendor/twig/twig/src/Environment.php(125): Twig\Environment->setCache(false)
#1 /homepages/17/XXX/htdocs/dav/baikal/Core/Frameworks/Flake/Util/Tools.php(368): Twig\Environment->__construct(Object(Twig\Loader\ArrayLoader))
#2 /homepages/17/XXX/htdocs/dav/baikal/Core/Frameworks/Flake/Core/Template.php(48): Flake\Util\Tools::parseTemplateCode('

XXX = my correct db

http://mydomain/baikal/html/admin/
The config.system.php-File in the Specific-Folder shows the right access-values from the db.

What can I do?
Oliver

[ByteHamster]

Hmm, the class that is not found on your device is definitely there in the release zip. Looks like you either did not upload the right zip file or it only got uploaded partially.

[dreizehnb]

Okay. Thank you. I solved the problem. In my FTP program there was still a filter set that excluded some files.