Not sure whether this has been fixed, but in early versions there used to be a bug that prevented progress through the Aegis questline if the following conditions were met:
- Arch keep unlocked, Oldfield goes inside
- Take technician's radio
- Take Oldfield's Navcom
- Investigate Nexus of Technology and report to Oldfield in person
- Investigate Horticulture Center
- Investigate Lemurian Hospital
After that, Oldfield always stays inside Arch keep, does not contact you about other missions, and it becomes impossible to report new discoveries to him. This also stops savage invasions.
If join pirates at this point, you can also ask "Where are you, professor" through Navcom, and he will respond, but other options block you.
