Call to a member function on a non-object

Error Message:

Fatal error: Call to a member function on a non-object in /YOUR/PATH/TO/fogbugz/Website/ThistleCConnection.php on line 84

Details:

The application.data file in /YOUR/PATH/TO/fogbugz/Accessories is probably blank.

Solution if you're upgrading:

During upgrade, setup makes a backup of your old 3.x FogBugz folder and names it fogbugz.1.

So, look in /YOUR/PATH/TO/fogbugz.1/Accessories for a copy of application.data that isn't blank, and replace the blank one with it.

Solution if you're NOT upgrading:

Setup may not have permission to write to the application.data file. Run these commands to grant permissions.

You can recreate the application.data file by adding the following lines to it:
sConnectionString:Driver={mysql};Server=localhost;Database=fogbugz;Uid=fogbugz;Pwd=fogbugz;
sRegistryVersion:4
fDemo:0
sURL:http://localhost/fogbugz
fProduction:0
fDebug:0
dtLastChecked:2005-01-01 00:00:00
dtLastHeartbeat:2005-01-01 00:00:00

Make sure the file is read/writeable by your apache user.