iframe flash flagallery doesn't work after site moved to new server

Our hosting serice just moved us to a new server with php 5.4 and we are trying to resolve a number of bugs.
We have flash gallery plug in installed on the English-language site https://www.peteranne.it and the galleries “built” here, i.e. they are in directories at the peteranne.it levels.
To display galleries on Italian and German language sites on our multisite we used iframe command eg
<iframe src=” https://www.peteranne.it/wp-content/plugins/flash-album-gallery/facebook.php?i=19&#8243; scrolling=”no” width=”600″ height=”250″></iframe> on the page https://www.peteranne.it/de/klettern/
This now gives error on the page
“Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at [email protected] to inform them of the time this error occurred, and the actions you performed just before this error.” Our ISP seems unable to send server logs to say what is wrong..
Can anyone suggest how to resolve this problem please? thanks Peter

More information about this error may be available in the server error log.”