It appears you do not have "Shared Logistics" treaty signed with the purple empire. This treaty is needed for you to be able to upgrade your units on their territory. As about the tooltip and the information written there, an issue has been filed for this bug.
Olari
Fanatic Survivor
Endlessly Entertained
Olari
Fanatic Survivor
43 800g2g ptsReport comment
Why do you report Olari?
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Newcomer
DEVClankerBanker
Newcomer
2 700g2g ptsReport comment
Why do you report ClankerBanker?
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