protonvpn RuntimeError: Couldn't find acceptable executables for {'xdg-open'}

**EDIT #3**: After a series of attempts at removing packages, and installing again with/without the virtualenv, I came across various hurdles, which required me doing (with the help of ref , ref ) $ conda install -c conda-forge pygobject $ conda install -c conda-forge gtk3 At one point, with some combination of actions and configuration (which I cannot reproduce now), I *seemed* to have overcome the error reported, but I was not able to connect to VPN. After further attempts I am again at the original point. **EDIT #2**: $ sudo apt install -y python3-gi python3-gi-cairo gir1.2-gtk-3.0 [sudo] password for user1: Reading package lists... Done Building dependency tree Reading state information... Done python3-gi is already the newest version (3.36.0-1). python3-gi-cairo is already the newest version (3.36.0-1). gir1.2-gtk-3.0 is already the newest version (3.24.20-0ubuntu1.1). 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. **EDIT**: I followed the answer by GADER. Now I get $ protonvpn-gui Traceback (most recent call last): File "/home/user1/anaconda3/bin/protonvpn-gui", line 5, in from linux_gui.protonvpn_gui import init File "/home/user1/anaconda3/lib/python3.9/site-packages/linux_gui/protonvpn_gui.py", line 9, in import gi ModuleNotFoundError: No module named 'gi' As evident, the python used is from anaconda (and I hope the update didn't break anything). I still have to debug the new error. **Initial OP** I installed protonvpn-stable-release_1.0.1-1_all.deb in Bodhi Linux, kernel 5.13.0-39-generic #44~20.04.1-Ubuntu SMP, with $ sudo gdebi protonvpn-stable-release_1.0.1-1_all.deb Note that this was done under a (base) virtualenv from anaconda, and this might have caused trouble. When I try to run protonvpn (or protonvpn-cli or protonvpn-gui), I get $ protonvpn Traceback (most recent call last): File "/usr/bin/protonvpn", line 11, in load_entry_point('protonvpn-gui==1.7.0', 'console_scripts', 'protonvpn')() File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 490, in load_entry_point return get_distribution(dist).load_entry_point(group, name) File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2854, in load_entry_point return ep.load() File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2445, in load return self.resolve() File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2451, in resolve module = __import__(self.module_name, fromlist=['__name__'], level=0) File "/usr/lib/python3/dist-packages/protonvpn_gui/main.py", line 16, in from protonvpn_nm_lib.api import protonvpn File "/usr/lib/python3/dist-packages/protonvpn_nm_lib/api.py", line 6, in from .core.report import BugReport File "/usr/lib/python3/dist-packages/protonvpn_nm_lib/core/report/__init__.py", line 1, in from .bug import BugReport File "/usr/lib/python3/dist-packages/protonvpn_nm_lib/core/report/bug.py", line 7, in from ..subprocess_wrapper import subprocess File "/usr/lib/python3/dist-packages/protonvpn_nm_lib/core/subprocess_wrapper.py", line 123, in subprocess = SubprocessWrapper() # noqa File "/usr/lib/python3/dist-packages/protonvpn_nm_lib/core/subprocess_wrapper.py", line 34, in __init__ self.__ensure_executables_exist() File "/usr/lib/python3/dist-packages/protonvpn_nm_lib/core/subprocess_wrapper.py", line 81, in __ensure_executables_exist raise RuntimeError( RuntimeError: Couldn't find acceptable executables for {'xdg-open'} (base) [user1@Orion:/mnt/shared_data/Downloads]$ But I do have a suitable xdg-open $ type xdg-open xdg-open is /usr/bin/xdg-open unless the problem is with versions. **How can I solve this?** I saw other reports of RuntimeError: Couldn't find acceptable executables for ... (source , source ).