Error 500 after update to Joomla 3.5.1

Upgraded site test.fotogamma.be from Joomla 3.4.8 to 3.5.1


Updated LessAllronder to 2.2.0 , assigned the template to all menus and saved the settings with success

Now my site gives an error 500 on the homepage.

When I select de default protostar template then there are no errors.

So what is the problem ?

A 500 error is an internal server error. That means for example that the memory consumption of the script was to much or the script timed out. You can see the exact reason in your server error log file. If you don't have access to that, you may have to ask your hoster.

With errorlogging enabled, the homepage shows a fatal error libraries/joomla/filter/input.php on line 233
Found that the "ARI Image Slider" module causes this problem .

Now checking for a new version of that module

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