the 1487simnel uprising recieved support from Ireland, Scotland, HRE, and Burgundy. Burgundy's support was very unusual as they historically supported England i.e. 100 years war.
despite Henry crushing the rebellion at the Battle of Stoke, the uprising was a warning to henry about the vulnerability of his kingship, especially when claimants were supported by other nations.
this showed henry needed to watch out for his neighbours, but did not threaten any of his recent truces with france, Scotland, or the HRE