Getting "Page Not Found" After Enabling the Devel Module Drupal 7
the theme developer module has not been touched in years and it is unsupported. You should not expect it to work at all and it is certainly plausible that it will have detrimental effects on your site. 

Unfortunately I suspect that you are out of luck unless you want to dig into the code yourself and attempt to get the module into a working state that does not blow up your site.