We have not yet released any binary compatible with XCode 9.
XCode 9 introduced changes in the standard library that is incompatible with old version of ROOT. There is a slight chance, depending on which plugin you need and which exact version that ‘just’ reconfigure and recompiling from scratch.
If it doesn’t you will need to use the master with commit 263508429dec26449513914e71f0f71c9ce9485f or newer.
Cheers,
Philippe.