In a multiple choice question when I switch the 'Other' option to 'on' the preview and also the test results in a sever error :
SurveyController kan de opgevraagde view "/survey/questions/questions/multiplechoice/columns/column_header" niet vinden.(English: SurveyController can not find etc.)
Switching off the 'other' option solves the problem, but that is not what I want and not what the option is intended for

just update to last version.

I use the latest version (Versie 2.50+ Build 160405)

then it will be fixed in next release.
If you can't wait, copy the content of this zip file in your root directory installation :
comfortupdate.limesurvey.org/patches/mul...e_patch_20160407.zip

Unfortunately this doesn't solve the problem

make sure that you overwrote existing application directory.

I did. Still the same. Sever error when 'other' is switched on.

can you post a screenshot of the error message please ?

Here it is.

editing...

It is a standard install in a subdomain. Yesterday I updated from a 2.06 install according to the procedure described in the manual.

ok, this one will be the good one:
comfortupdate.limesurvey.org/patches/mul...ce_columns_patch.zip