After upgrading from 1.9.5+ to 2.0, one wiki of one course (say, course A) when clicked on points towards the wiki of another course (say, course B). Other wikis of the same course (i.e. A) do not behave in this manner. After the concerned wiki of course B is deleted from the test installation, the following error is thrown when the concerned wiki of couse A is clicked:

Notice: Trying to get property of non-object in /moodle/mod/wiki/create.php on line 48

wiki/invalidwikiid

More information about this error (clickable, points to http://docs.moodle.org/en/error/wiki/invalidwikiid)

Stack trace:
line 421 of /lib/setuplib.php: moodle_exception thrown
line 49 of /mod/wiki/create.php: call to print_error()