I played windowed and I noticed the planets disappeared after swapping back and forth a couple of times but could continue to play and planets would appear again when ships were launched.

I invaded a planet from the YOR and got string not found error

After playing like this for a while a got an invalid call dialog and the screen went black with just the dialog beeing displayed.

Info from debug.err :

Debug Message: Destroying ship Starbase 473. Orbiting: 0
Debug Message: Destroying ship 3-Constructor M2-4 1138. Orbiting: 0
Debug Message: Error. String Not Found. Table: Dialog String Name: HumanPlanetConquered
Debug Message: Destroying ship 5-Troop Transport M2-4 1133. Orbiting: 0
Debug Message: Error flipping back buffer to primary buffer.
Debug Message: Device lost
Debug Message: ValidateDevice::Reset
Debug Message: Invalid call
Debug Message: Main Shell terminating normally
Debug Message: Unallocated Mem: 128 bytes of memory from line 222 of .\Source\parse.cpp
Debug Message: Not all memory has been freed from memory system Parse.
Debug Message: 128 bytes of memory still allocated.
Debug Message: Unallocated Mem: 44 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 46 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 46 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 45 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 47 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 46 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 45 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 46 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 48 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 42 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 46 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 45 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 48 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 48 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 8 bytes of memory from line 1112 of .\Source\editfields.cpp
Debug Message: Unallocated Mem: 56 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 48 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 56 bytes of memory from line 1340 of .\Source\ListBox.cpp
Debug Message: Unallocated Mem: 8 bytes of memory from line 1112 of .\Source\editfields.cpp
Debug Message: Unallocated Mem: 8 bytes of memory from line 1112 of .\Source\editfields.cpp