Well...
 REM ...AT. worked since an AT entry was present in the TAL output
 INS $BIGIND not
 INS -- File not found
 Disk (RD51) has 850 blocks free after some cleaning up. It had 738 before. 
  Thank for your answer.
 I'll try your suggestions.
 It's RSX-11 and I've found some troubles on the disk.
 I ran VFY with the /RC option.
 Some files can't be read (it reports -4 and -101 errors, parity error
 and forced error mark).
 INDEXF.SYS itself appears to have a bad spot.
 So I'm tempted to backup all relevant data and reinstall.
 BTW there's no [3,54] on the fixed disk. 
Ok, if you don't have [3,54] then you must have RSX-11M not RSX-11M+. In that case you
should have two versions of Indirect:
[1,54]ICP.TSK
[1,54]ICX.TSK
ICP.TSK is the default, "full capacity" version and in V4.0 of RSX11M it shows
up under TAS as:
 TAS ...AT. 
...AT. 1.0    GEN     64. 00060000
LB0:-00114253
so try removing it as you did above and then INS the ICX.TSK and try it.
 REM ?AT.
INS [1,54]ICX.TSK
TAS ?AT. 
...AT. 9.01   GEN     64. 00060000 LB0:-00114033
It would be good to know which version of RSX-11M you have and also a bit about the
configuration.
You mention backing up your data, what disks do you have? To back up a system disk
sometimes
it is best to use BRUSYS.SYS which on M should be in [1,51] It is a memory resident
version
of BRU (running under RSX11S) that you BOOT and then can copy disks.
Good Luck!
Mark