[TYPO3] rte disappeared :(

[Horn Gábor]

Hello,

i run into a "little" problem whle upgrading an old site from 3.6.2 to 
first 4.1.7 then 4.2.1. The problem is rte disappeared, neither the (now 
sysext) rtehtmlarea nor tinyrte works, i just see plain textareas. I 
deleted everything from typo3temp/, i removed rtehtmlarea from 
typo3conf/ext/. Versions according to the EXT manager are 1.7.5 
(rtehtmlarea) and 1.7.2(tinyrte).
I'm affraid something is kinda broken here, but i don't find any 
relevant error messages to start work with (even checked php log on the 
server and js window in browser). This is a very old site and database 
is in latin1 can that be the problem? If it's not any suggestion please 
where should i look for the problem?

thanks, Gábor Horn