While using SXA v1.7.1 in the experience editor we sometimes were getting plagued by this exception after attempting to edit the style/grid parameters of a rendering on the page. It appears that some sort of double encoding is occuring when the layout details are being posted back to Sitecore.
[FormatException: Guid should contain 32 digits with 4 dashes (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx). Actual value: %7B113BEF7C-97E6-46CA-8CF3-916F7FAA8DE2%7D]
Sitecore.Data.ID..ctor(String id) +207
Sitecore.Data.ID.Parse(String value) +59
System.Linq.WhereSelectArrayIterator`2.MoveNext() +145
System.Linq.WhereEnumerableIterator`1.MoveNext() +124
System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +436
System.Linq.Enumerable.ToList(IEnumerable`1 source) +69
Sitecore.XA.Foundation.Grid.Commands.ShowGridPropertiesDialog.FillGridParameters(NameValueCollection contextParameters, DeviceDefinition device, NameValueCollection parameters, String fieldName, String value) +551
Sitecore.XA.Foundation.Grid.Commands.ShowGridPropertiesDialog.UpdateLayout(NameValueCollection contextParameters, FieldEditorOptions fieldEditorOptions) +893
Sitecore.XA.Foundation.Grid.Commands.ShowGridPropertiesDialog.Run(ClientPipelineArgs args) +160
We have implemented a temporary workaround by overriding the ShowGridPropertiesDialog command and checking each guid and decoding it if required.
Is this a bug?