I started to get a following error from the PI SMT Archive Editor when trying to access three String-type tags:
About a month ago I have set up an UFL Interface to read data from .txt log files and store the read messages into 3 PI Tags. When I tested the Interface it read the data successfully and send it to PI slowly populating the associated PI Tags with new values (when the log files updated). Both the Current Values as well as Archive Editor were showing new messages stored in PI Tags.
The Interface is still running correctly with no errors reported on its side and I can see that the messages are being sent to PI Tags. When I look into Current Values in SMT I can see the Timestamp and registered Values changing also Stale and Bad Point don't point these 3 PI Tags as stale.
Yet when I try to view the previous values registered in those PI Tags through Archive Editor I see an error as shown above.
Note all other PI Tags both numerical and string-type on the same server seems to working fine and I can view them in the Archive Editor.
Any Idea what has happened ?