I get an error message trying to install the paid version of Form maker:

"Siirretty tiedosto ylittää php.ini:ssä määritellyn upload_max_filesize -direktiivin."

Goes something like this (sorry for bad translation):
Tranferred file size exceeds the upload_max_filesize in php.ini

And then nothing happens.

How do I install the Form maker to my site?

Solved this by myself.

Dear Katri,

I am guessing you have resolved the issue by enlarging the value of upload_max_filesize directive in php.ini file of your website. In any case, it is fantastic, that the problem was figured out!

Please feel free to let us know any time you have questions or support requests.
Thank you!