I discovered a problem, created by the developer, which is caused an invalid tag error.
During the process of building the HMI screens, I was copying the tag names from an old system and pasting them into the new. Some of the tags ended up with a trailing space. This caused a failure to read tag error. I did a quick fix by modifying the controls I was using (modified control's properties by adding X = Value.Trim). This was faster than going through each screen control and looking for and removing the trailing space.
It would be a nice addition if this fix was added to future releases to prevent development error caused by unawareness.