I made a post in 2013 asking about moving cards from one collection to another. Although being able to do this in some type of mass never happened, I recently caved and manually added each card to a separate one (for PSA graded singles). In doing this I observed:
All details/tables with info like gradeco/grade/condition/comment etc transferred properly
Photos transferred properly in gallery view, but thumbnails were not visble. I went through and manually did drop down and View/AddImage to each one. After that screen loaded thumbnails were visible again.
Also I use the "Graded cards in your collection" link often since unlike normal collection I can see all cards in 1 list instead of them being separated by set/etc. I noticed even if a thumbnail can be seen properly, if you click on the thumbnail it will give a broken image icon, but if you right click "open link in new tab" it will show the full size image properly in that tab.
Not sure if these are simple missed PHP coding errors or what since I'm not diving into the code, but just thought you'd want to know. Not picking or anything. I love the site thank you.
Anyone curious to see a humble 324 card PSA football collection of mainly HoFers from 1960s-2015 looks like (Almost all Topps/Chrome/Heritage/Archives) then check it out:
List:
https://www.tradingcarddb.com/ViewCollectionMode.cfm?Member=FrankCastleAZ&MODE=GRADED&Type=Football&CollectionID=3&Filter=G
Gallery:
https://www.tradingcarddb.com/CollectionModeGallery.cfm?Member=FrankCastleAZ&MODE=GRADED&Type=Football&CollectionID=3&Filter=G
Collector since 1990. Specializes in raw or PSA graded Football, Basketball, Hockey, Formula1, and Wrestling (mainly Topps/ToppsChrome/ToppsHeritage/ToppsArchives)