Glass Mapper "Unrecognized Guid format" error on MapPropertiesToObject

Question

I'm getting an error from GlassMapper on certain pages in my Sitecore solution.

    public override void Execute(ObjectConstructionArgs args)
    {
        // check that no other task has created an object and that this is a dynamic object
        if (args.Result != null || args.Configuration.Type.IsAssignableFrom(typeof(IDynamicMetaObjectProvider))) return;

        // create instance using your container
        var obj = ServiceLocator.ServiceProvider.GetService(args.Configuration.Type);

        // map properties from item to model
        args.Configuration.MapPropertiesToObject(obj, args.Service, args.AbstractTypeCreationContext);

        // set the new object as the returned result
        args.Result = obj;
    }

The error is occurring on args.Configuration.MapPropertiesToObject(obj, args.Service, args.AbstractTypeCreationContext); - System.FormatException: Unrecognized Guid format.. This error is only occurring on pages of a particular template, but not ALL pages of that template and I'm not sure how to track down which field is causing the guid error

Answer 1

I experienced the same error when a General Link field didn't contain any id="{xxx}" attribute or had it empty like id="". So, I suggest to check the raw value of the link fields on the failing pages.