Table TCURR is locked by user &

What causes this issue?

You want to enter exchange rates for a worklist.
At present, however, it is not possible to enter exchange rates for any
worklist, as user & has locked table TCURR using the old exchange rate
entry transaction 0808.
To allow two or more users to enter exchange rates simultaneously, all
users must use the new transaction TCURMNT.
Otherwise, it is only possible for one user at a time to edit
worklists.
Note, however, that only one user can edit a given worklist at any one
time.

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

System Response

How to fix this error?

Wait until user & has finished entering his/her exchange rates and has
left transaction 0808.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.