Updated for 26.1 for STU3, R4, R5
Forge R4 can not extend value[x] elements (FOR-479)
When adding an extension, refresh might be necessary for showing and
editing all options on extension. (FOR-420)
When moving to the Dependencies tab on a Forge project, the interface
might refuse to switch back directly to the Project tab. Please click
in the packages window below first and then try again. (FOR-395)
HL7 is maintaining a known issue list for the FHIR specifications on their Confluence.