Table locked > See restart log (old) < Read long text

What causes this issue?

The table may not be converted or be processed with the database utility
at the moment for security reasons. There is a restart log which can be
evaluated with the menu option <LS>'Old restart log' </>.
<LS>Error cause:</> table conversion which was carried out with the old
conversion procedure (release level before Rel. 3.0) was terminated at
the time. The system therefore <LS>locked</> the table against further
processing by the database utility.

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

<LS>Data might be lost!</>

System Response

The table is locked against further processing by the database utility.

How to fix this error?

Evaluate the restart log. For the above-mentioned reasons, you must
search under <LS>'Old restsart log'</>.
General instructions for correction:
>>> If no restart step was marked or if the conversion only reached
step 3 at the most(!!):
Select 'Unlock' in the popup of the restart log. You can then process
the table again.
>>> If conversion reached at least step 4:
Select 'Restart' in the popup of the restart log. Table conversion
continues according to the old procedure (< Rel. 3.0). <LS>Do not select
'Unlock' now or data might be lost. </> The conversion is either
successful or an error message (e.g. an ABAP - Dump or a SYSLOG) gives
further information about the error.

Error message extract from SAP system. Copyright SAP SE.