You should be using the z3c.ptcompat
package instead.
The z3c.form.ptcompat
module was removed for the z3c.form 2.5.0 release in October 2011.
When using z3c.ptcompat
, replace your import with:
zope.browserpage.viewpagetemplatefile import ViewPageTemplateFile
widget.template = ViewPageTemplateFile("templates/minmax.pt")