[ACE] Error Extension not found. [Return Code: -1]

[Markypops]

Just installed ACE 3.18.1 through steam. When playing solo or joining my friend's server. The game always throws [ACE] Error Extension not found. [Return Code: -1]

I tried repairing, reinstalling the mods, and reinstalling the game along with the mods as well to see if it fixes it but it did not.

Here's a log that showed a warning that might help:

[ WARN] 22: InsituUgcModSynchronizationStrategy: System.ArgumentNullException: Value cannot be null. Parameter name: String at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal) at System.Number.ParseUInt64(String value, NumberStyles options, NumberFormatInfo numfmt) at Utils.GameData.MetaCppReader.Helper.GetUint64(IEnumerable1 dic, String name) at Utils.GameData.MetaCppReader.Cast(ICollection1 keyValuePairs) at Utils.GameData.MetaCppReader.Load(String path) at Launcher.Extensions.InsituUgcModSynchronizationStrategy.DetectChanges(ExtensionInfo extension, String installDirectoryBySteam)

Thank you