Updating to v3.0.6 failed, fails with internal server error

I tried my first update of flexicontent.
when updating from 3.0.4 to 3.0.6 I see:
"Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request."

I tried the update by upload from my computer and from "tmp". And I used the Joomla-Update-function.
What is wrong? Is there an update-function in flexicontent?
I´m rather used to Joomla. But Flexicontent is really exiting!
Thanks for your help.
Dorothea

Hello

try installing Akeeba admin tools and clicking "Fix folder permissions"

I installed Akeeba and fixed folder permissions. Same Error. I deleted htaccess password. Same error.
Do you have another idea?
thank you!

Hello the only sure way to avoid guessing is to look at the Apache serverlog

I can´t find or create the Apache serverlog. (1&1 - Hosting)
What can I do?
My configuration:
Joomla 3.4.3
PHP Version 5.6.10
Flexicontent 3.0.4

Hello

ask your webhosting support

tell them that you need to be able to view apache server log, to
be able to see the reason for an "internal server error"

- but also aks them how to be able to view the log without them telling you, i mean to be able to view it yourself whenever you need