In hindsight, and I believe this has already been discussed, the problem stems from certificates following a change in how the installer (innosetup) handled them when upgrading to version 2.3 (to be confirmed by the Tranquil-IT team).
Without being an expert, it seems to me that at some point there was a problem distributing the certificates used to sign packages and communicate with the server. As a result, a stable situation became impossible. It's probably possible to redeploy the server's certificates to the agents, but that's beyond my expertise.
Perhaps a possible solution:
On a machine with a correctly functioning agent, compare the contents of the directory c:\program files (x86)\wapt\ssl and c:\program files (x86)\wapt\private and copy everything into the directory of a machine where the agent is malfunctioning. Restart the wapt service and run another test... This comes with no guarantee of success or a clean installation.
For me, uninstalling and reinstalling the agent wasn't enough; I also removed the entire server component (programs, configuration, certificates, database). It's fairly simple because my server only offers wapt; you just need to know the correct commands on Debian and where the files and databases are located to perform the final cleanup.
But you must follow the order carefully:
- Delete the machines via the console;
- Uninstall the agents;
- Verify that none of them have re-registered;
- On the server, stop all wapt processes;
- Uninstall wapt on the server;
- Uninstall PostgreSQL and nginx (for Linux; I don't know if it's the same on Windows).
- On the server, go through the system directories to delete everything related to wapt, postgresql, and nginx.
When in doubt, reboot (although it's completely unnecessary on Linux).
As it stands, you're almost on a freshly installed server, and all that's left is to install the server layer and then deploy the agent.
Unfortunately, since we're using the Discovery version, there's little to no support from the Tranquil-IT team, which is normal (and don't take this as a criticism) since it's the free version. They generate revenue and funding through the Enterprise version.
In practice, the machines in my network that gave me trouble during my tests were often VMs. Whether they were managed by VMware on a hypervisor or on my PC managed by VirtualBox. Is that the cause? I don't know. Perhaps it's a clue for future development of Wapt.