A large ring gate appears on Earth that leads to other planetary bodies that vary between being able to sustain human life and just barely allowing humans to exist on the planet for a while.
Another sentient lifeform exists on the planets. The quick and dirty is that they are only capable of moving and living on a sludge-like liquid. If the sludge is in high enough concentrations, the local atmosphere is saturated with particles that are toxic to humans but beneficial to these organisms.
Most importantly, advanced digital computers simply do not work. Either bringing a computer from Earth or building one natively on a planet yields a machine that either doesn't turn on or is inconsistent in operation at all times. Note that this is in reference to advanced digital computers that explicitly use a lot of software. Something like a smartphone isn't going to work. Things like calculators, and some digital computers that use lower-level software work (think pre-2000/late 90s). Analog computers work planet-wide. However, machines that make use of heavy/high level software (ie. levels above say assembly or C) don't work. Note that not "working" in this case doesn't have to mean that the machine is frying itself. It could mean something as simple as a computer is always giving wrong or erroneous output.
What is causing my advanced digital computers that rely on advanced software from working planet wide when simpler analog and digital computers work?
The goal here is to stop advanced software-based machines and solutions from ever working on such planets. Things like AI based drones or automated machine learning based factories are impossible on such planets. A planet wide internet network that mirrors ours today is impossible. The cost of human labor in settling the planet, economic, and military sectors is a major point for the setting. Computer technology resembles that of the pre 2000s ideally due to the effects.
Somethings that might help form an answer:
- There is significant radio interference due to properties of the atmosphere and clouds. Long range communication is done through wires. Short range communication can be handled through radios.
- The organism on the planet that utilizes the sludge releases a particle that can interfere with radio waves. Killing off massive portions of the organism and sludge throw up particles into the atmosphere that impact weather. But they're manageable for humans. An answer can utilize or even add effects to the particle if need be.
- There are minerals, particles, biological compounds and elements that are completely alien to Earth.