The project is still under heavy development. I suggest starting it from the command-line. There you will get a detailed log stream, thus if there is any problem, it makes debugging easier.
In the log you can also find some useful information, e.g. location of the settings file, location of the categories file, etc.
$ jive
INFO 2018-06-30 19:44:31 jive.check_api_keys() [1989]: tumblr API key was found
INFO 2018-06-30 19:44:31 jive.check_api_keys() [1997]: imgur API keys were found
INFO 2018-06-30 19:44:31 settings.read() [30]: /home/jabba/.local/share/JiveImageViewer/settings.json was read
INFO 2018-06-30 19:44:31 categories.read() [24]: /home/jabba/.local/share/JiveImageViewer/categories.yaml was read
DEBUG 2018-06-30 19:44:31 cache.debug() [67]: number of images in the cache: 232
DEBUG 2018-06-30 19:44:31 cache.debug() [69]: cache size in bytes: 99,681,981
INFO 2018-06-30 19:44:31 categories.read() [24]: /home/jabba/.local/share/JiveImageViewer/categories.yaml was read