Many players who install Everytime Submarine get errors trying to load their saves (sample report). Investigate, submit a pull request if applicable, and mark the broken version incompatible.

See sample save and content pack.

This happens when loading the save, specifically when the game tries to set the fixed beach bridge and gets tile index 301 from tilesheet index 1.

When the mod isn't installed, the tilesheets are [0]=Paths [1]=untitled tile sheet, so that correctly uses untitled tile sheet (which is Maps\\spring_beach). When the mod is installed, the tilesheets are [0]=night_market_tilesheet_objects [1]=Paths [2]=untitled tile sheet, so that incorrectly tries to get the bridge textures from the Paths tilesheet which doesn't have that many tiles.

The fix is to rename the custom tilesheet to add a z_ prefix, as recommended on the modding page. I'll let the author know, and mark the current version incompatible since it prevents players from loading their saves.

Done in develop for the upcoming SMAPI 2.6.1 or SMAPI 2.7.