So you get the 'please wait message ' ?
If so from that page right click and select 'save page as' then select save to a folder on PC usually the download folder make a note of the filename.
Open Adobe reader DC, the select file, then select open, then select the filename you saved above and the form should open. You even even just post the link from the 'please wait message page' into Abobe reader DC.
If I misunderstood your issue apologies but this just worked for me opening IMM1294