Platform: PC / Windows
Format: Historic Traditional / Best-of-Three

Issue:
The MTG Arena client freezes on “Waiting for the Server…” when I try to open a specific Historic deck in the deck builder. The deck can be imported/created and can even be played in matches, but after saving it, trying to open or edit the deck causes the client to remain stuck on “Waiting for the Server…”.

Steps to reproduce:
1. Create or import the following Historic Traditional deck.
2. Save the deck.
3. Leave the deck builder.
4. Try to open the same deck again from the Decks screen.
5. The client gets stuck on “Waiting for the Server…” and the deck editor never opens.

Actual result:
The client hangs indefinitely on “Waiting for the Server…”. I have to close/restart the client.

Expected result:
The deck should open normally in the deck builder and be editable.

Additional notes:
The deck appears to be playable in matches, but the deck editor cannot reopen it. I also tried rebuilding the deck manually, and the same issue happened again. While rebuilding, the issue seemed to appear around the moment I added Shatter the Sky, after which searching/opening the deck became unreliable. I am not fully sure whether Shatter the Sky is the cause or whether it is an interaction with other cards in the list.

Decklist:
Deck
4 Agent of Treachery
1 Massacre Wurm
1 Cavalier of Dawn
1 Dream Eater
1 Gravebreaker Lamia
4 Thoughtseize
3 Fatal Push
1 Vanishing Verse
4 Faithful Mending
4 Tainted Indulgence
4 Necromancy
2 Ephemerate
2 Shatter the Sky
2 Teferi, Hero of Dominaria
4 Watery Grave
4 Hallowed Fountain
4 Godless Shrine
2 Raffine's Tower
3 Drowned Catacomb
1 Glacial Fortress
1 Isolated Chapel
1 Shipwreck Marsh
1 Takenuma, Abandoned Mire
1 Otawara, Soaring City
2 Island
1 Plains
1 Swamp

Sideboard
2 Duress
2 Dovin's Veto
2 Mystical Dispute
2 Go Blank
2 Portable Hole
1 Divine Purge
1 Ritual of Soot
1 Farewell
1 Memory Deluge
1 Shark Typhoon

Workaround:
No reliable workaround found. Rebuilding the deck manually did not fix the issue. The only partial workaround is to avoid opening/editing the deck after saving it, but this makes sideboard/deck changes impossible.