Maintenance for the week of November 3:
• NA megaservers for maintenance – November 3, 4:00AM EST (9:00 UTC) - 12:00PM EST (17:00 UTC)
• EU megaservers for maintenance – November 3, 9:00 UTC (4:00AM EST) - 17:00 UTC (12:00PM EST)
• ESO Store and Account System for maintenance – November 3, 4:00AM EST (9:00 UTC) - 12:00PM EST (17:00 UTC)
• https://forums.elderscrollsonline.com/en/discussion/684716
Put them all back into your bank and then back again into your inventory. Should fix it (until the next login).
Not sure if and when the addon author will fix the code.
Also look at the comments on esoui's addon page, someone provided a unofficial fixed version that works.
Edited by anitajoneb17_ESO on 31 August 2019 11:03
For me, I had to re-download the add-on. Also, after installing the add-on, open map (M) and go to filters and make sure that
"Lost Treasure Maps" & "Lost Treasure Survey Maps" have "✓" mark & are enabled.