Hello romank,
the workaround you could do right away is called 'Manually pre-install PDF fonts':
1 - Download the following file 'pdffonts.zip':
vi-solutions.de/index.php?option=com_vis...er&linktype=pdffonts
2 - Unzip the file 'pdffonts.zip'.
It contains the 'fonts' directory.
3 - Copy the 'fonts' directory to the following directory within the Joomla instance:
media/com_visforms/tcpdf
4 - The result is the following directory path:
media/com_visforms/tcpdf/fonts
Now start the installation of the Visforms Subscription.
If the directory 'media/com_visforms/tcpdf/fonts' and the file 'helvetica.php' contained therein are present, the PDF fonts will not be installed.
Kind regards, Ingmar