if you install - especially older - FacileForms packages, make sure the id-attribute is set like
<FacileFormsPackage id="rvbBMI" type="autoincrement" version="1.5.1 Beta">
Otherwise the form won't be installed!
If such an id is missing then just add it, best would be to use the name you find in the <name> tag a few lines below in the package xml file.