Want of jurisdiction and forum non conveniens.

Dundee Precious Metals Inc. v. Marsland, 2011 ONCA 594 has a helpful review of jurisdiction and forum:

JURISDICTION

[4]              It is common ground that, pursuant to Van Breda v. Village Resorts Ltd. (2010), 98 O.R. (3d) 721 (C.A.), jurisdiction simpliciter is presumed as the claim falls within Rule 17(f)(2) ("the contract provides that it is to be governed by or interpreted in accordance with the law of Ontario"). To be successful, Marsland therefore bears the onus of demonstrating the lack of a real and substantial connection with Ontario.

[5]              Van Breda holds, at para. 84 that "[t]he core of the real and substantial connection test is the connection that the plaintiff's claim has to the forum and the connection of the defendant to the forum, respectively."
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FORUM NON CONVENIENS

[13]         As this court stated in Incorporated Broadcasters Limited v. Canwest Global Communications Corp. (2003), 63 O.R. (3d) 431 at para. 58:

The starting place for considering convenient forum is "whether there clearly is a more appropriate jurisdiction than the domestic forum chosen by the plaintiff in which the case should be tried" (Frymer at p. 79 O.R.). Also see Spar Aerospace Ltd. v. American Mobile Satellite Corp., 2002 SCC 78, 220 D.L.R.   at para. 69 and 70 and Amchem Products Inc. v. British Columbia (Workers' Compensation Board), [1993] 1 S.C.R. 897, 102 D.L.R. (4th) 96 at p. 921 S.C.R.