Ignore error loading mod in fetchMod

If a bad download or file transfer causes a mod in a host's mod folder
to become corrupt the attempt to load the mod will throw an error that's
not the file not existing.  This in turn causes starting the instance to
always fail as the mod is never attempted to be re-downloaded.

Fix by ignoring errors attempting to load mods already present in the
mods folder that aren't in the mod store so that a new download is
attempted after that fails.

CHANGELOG.md

@@ -14,6 +14,7 @@
 - Fixed data export with a mod using shorthand notation for the default value of a color-setting causing the ModPack data to be set to invalid data.
 - Fixed per user per instance player stats not being deleted when the instance it's for is deleted.
 - Fixed mods setting the item prototype icons property to an object mapping instead of an array breaking the data export.
+- Fixed a bad mod in the host's mods folder causing instance start to fail instead of the host re-downloading the mod.
 
 
 ## Version 2.0.0-alpha.16

packages/host/src/Host.ts

@@ -600,8 +600,9 @@ export default class Host extends lib.Link {
 		try {
 			modInfo = await this.modStore.loadMod(mod.name, mod.version);
 		} catch (err: any) {
+			// A broken zip file may have been left in the mods folder
 			if (err.code !== "ENOENT") {
-				throw err;
+				logger.error(`Error loading mod ${mod.name} ${mod.version}: ${err.message}`);
 			}
 		}
 		if (modInfo && (!mod.sha1 || mod.sha1 === modInfo.sha1)) {