Invalid topic space '&1'. Enter exactly 3 segments (A-Z, a-z, 0-9)

Message type: E = Error

Message number: 065

Message text: Invalid topic space '&1'. Enter exactly 3 segments (A-Z, a-z, 0-9)

What causes this issue?

The topic space entered is invalid.
Examples for invalid topics space:
1. /S4
2. S4/WDF/ERP1/
3. S4/WDF/E RP1
4. S4/*

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Ensure that you maintain the topic space based on the below criteria.
1. Topic spaces must consist of one or more segments that are case
sensitive.
2. Forward slash '/' (ASCII 0x2F) is used as segment separator. Topic
space must not begin or end with '/'.
3. Each segment must consist of 2+ characters: ?A-Z?, ?a-z? or ?0-9?.
Examples of valid topic spaces:
1. S4
2. S4/WDF/ERP1