Ok you didn 't answer all of my questions but given that you've tried the small project export then
import test I suspect the problem is permissions on the import folder so get whoever looks after your
installation to check/change that.
I'm guessing import doesn't work for anyone or any project?
I asked:
What template type were the zips exported from XOT or Bootstrap?
What version of Xerte were they exported from?
I asked because with a previous version/revision (I can't remember exactly which) there was an issue with
Bootstrap project import where the project would import but be treated as an xot project rather than
Bootstrap project and therefore not work but it doesn't sound like that's the problem in this case.
Suffice to say it isn't a problem with the Xerte code e.g. export and import should work fine so you need to get whoever looks after your installation to check the Xerte and wider configuration e.g. xerte path values and server temp path values, check permissions, check server logs etc
HTH
Ron