Did you actually install the parts and data?
cfranklin@cfranklin-Latitude-D630:~$ sudo apt search fritzing
[sudo] password for cfranklin:
Sorting... Done
Full Text Search... Done
fritzing/zesty,now 0.9.3b+dfsg-4 amd64 [residual-config]
Easy-to-use electronic design software
fritzing-data/zesty,zesty,now 0.9.3b+dfsg-4 all [installed,auto-removable]
Easy-to-use electronic design software (data files)
fritzing-parts/zesty,zesty 0.9.3b-1 all
Easy-to-use electronic design software (parts files)
cfranklin@cfranklin-Latitude-D630:~$ sudo apt-get install fritzing fritzing-data fritzing-parts
Reading package lists... Done
Building dependency tree
Reading state information... Done
fritzing-data is already the newest version (0.9.3b+dfsg-4).
fritzing-data set to manually installed.
The following NEW packages will be installed:
fritzing fritzing-parts
0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Need to get 9,513 kB/13.1 MB of archives.
After this operation, 151 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://us.archive.ubuntu.com/ubuntu zesty/universe amd64 fritzing-parts all 0.9.3b-1 [9,513 kB]
Fetched 9,513 kB in 5s (1,840 kB/s)
Selecting previously unselected package fritzing.
(Reading database ... 269382 files and directories currently installed.)
Preparing to unpack .../fritzing_0.9.3b+dfsg-4_amd64.deb ...
Unpacking fritzing (0.9.3b+dfsg-4) ...
Selecting previously unselected package fritzing-parts.
Preparing to unpack .../fritzing-parts_0.9.3b-1_all.deb ...
Unpacking fritzing-parts (0.9.3b-1) ...
Processing triggers for mime-support (3.60ubuntu1) ...
Processing triggers for desktop-file-utils (0.23-1ubuntu2) ...
Setting up fritzing (0.9.3b+dfsg-4) ...
Setting up fritzing-parts (0.9.3b-1) ...
Processing triggers for man-db (2.7.6.1-2) ...
Processing triggers for gnome-menus (3.13.3-6ubuntu5) ...
cfranklin@cfranklin-Latitude-D630:~$
I was having issues as well, until I had seen the parts and data packages. The built in GUI software manager doesn't show these.