It is a permission issue as the error states. Changing ownership for the svn folder and applying permission

It is a permission issue as the error states. Changing ownership for the svn folder and applying permission should solve this.

Open terminal and enter the following

sudo chown -R www-data:www-data /var/svnfolder/*
sudo chmod -R 770 /var/svnfolder/*

in my case it was

sudo chown -R www-data:www-data /rep/svn/*
sudo chmod -R 770 /rep/svn/*

Hope this helps