Arriving at an important moment without being ready is one of the most familiar dreams. It is read as performance worry rather than any real lack of ability.
Where in your waking life have you met something like this lately?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.