Errors/Chain errors
TooManySignatories
A chain-side capacity limit was hit; reduce the size or count of the request
The multisig signatory list exceeds the maximum allowed. Compare the length of other_signatories plus the sender against the pallet's MaxSignatories constant.
Declared by the Multisig pallet; it classifies to the semantic code limit_exceeded.
Remediation
A chain-side capacity limit was hit; reduce the size or count of the request
The same explanation is available in the terminal: btcli explain TooManySignatories.