I tried to install CedHighlightjs on J3.4.7
There is not any confirmation message when I send the file, and it's in the list of plugins but I can't click on it...
This may be some compatibility issue ? Or a problem linked with my configuration ?
I've tried to install on 3.4.8 windows/linux, php 5.6.16 and the plugin can be opened. and used. Did you use pkg_cedhighlightjs_j30_j31_j32_j33_1.0.1-free.zip ?
Can you check your "folder permissions" under /administrator/index.php?option=com_admin&view=sysinfo