MRDF-000 — Trying to subtitute a nonexisting string in a file
Sometimes the proxy needs to read a file and perform some string subtitutions in it. This feature is used, e.g., for passing customizable error messages to a client. The file is read twice.
During the first run, validity of substitution places in the file is checked and the total length of the file after substitutions is computed. In the second run, the substitutions are performed and the result is passed to the proxy for further processing. The set of substitution strings is provided by the proxy, the places for substitutions in the file are denoted by $1$, $2$, and so on. If the number of a string to substitute is greater than the actual number of available strings in the second run, this error occurs. It is a fatal error which causes the process to terminate, because the error should have been already detected in the first run.
Internal error.