sorry for the late peplay, i've a lot of work at the moment....
Binnenkort door naar 2.10 of 2.12?
yes, why not? it make's no sense, to work longer with older versions, because, there are too many changes in PHP in the last two years. i've the same problem actually with a old WB 2.8.0 and specially with the used modules and also with some trouble in the charset the most letters are correct translated, but not all. i think, the server charset change in the past, so that i've not all correct converted.
if you can, use PHP 5.6.x and change it at the last step, when you have WB 2.10 or newer. It's recommended, to use the lastest WB-Version 2.12.x. the hardest step with the most possible problems come's, when you upgrade from 2.8.3 up to 2.10. x. In all my upgardes, i've never problems, when i upgrade from WB 2.10.x to a newer version (if i solve all problems in WB 2.10.x)