SysErr and it always seems to want to kick you out of BR!
Cause:
One thing that will cause it is doing an exists(x$) when x$ has a length of 199.
CURFLD(14) where there are less than 14 available fields.
Remedy:
Trim it or copy it to a location with a shorter path name. You can probably cause the error with any path with a length more than the maximum length path that BR! allows!