OK.
So, try with one extension first: Clear history (hirei). Print out one extension, which gives command lost. Then SGSAI and SGSSI. Print again, if no command lost, proceed. Otherwise send HIMDP.
sgsai:sigar=1,signo=129,level=b,lcside=exe,stype=swsw,unit=der,lim=1,byte=0-0&1-0&2-1&3-a8&4-c&5-ff&6-x1&7-x2&8-x3&9-x4&10-x5;
sgssi:sigar=1;
x1-x5 is the directory number
byte 4 is the LIM number, which is missing (c in your case)
byte 5 = ff removes the info from the unit
below also a trace of this procedure
(H'0129)
FROM SGR (H'00A6) EXE A IN LIM 001
TO DER (H'017D) EXE A IN LIM 001
WITH 0 1 2 3 4 5 6 7 8 9
000 H'00 H'00 H'01 H'A8 H'0C H'FF H'02 H'00 H'00 H'09
010 H'0F H'02 H'00 H'07 H'4C H'02 H'00 H'06 H'00
Note! Every directory number has to be removed separately!