Argument data type text is invalid for argument of len

I don't understand why there's a such error there (marked in the code below).

I've tried to put this on comment but the error still occurs at line 64. I'm using sql server 2005.

Error :

Msg 8116, Level 16, State 1, Procedure prSwiftGetMessages, Line 64
Argument data type text is invalid for argument 1 of len function.

Code :

delete from Messages where LOAD_DATE >= @minDate print 'Deleted : ' + convert(varchar, @@ROWCOUNT)

print 'Date MIN = ' + convert(varchar, @minDate,102)

print 'Dropping Indexes.' 
if exists (select 'x' from sysindexes where name = 'idxMessagesReference')
      drop index Messages.idxMessagesReference 
if exists (select 'x' from sysindexes where name = 'idxMessagesLoadDate')
      drop index Messages.idxMessagesLoadDate 
if exists (select 'x' from sysindexes where name = 'idxMessagesBankTo')
      drop index Messages.idxMessagesBankTo 
if exists (select 'x' from sysindexes where name = 'idxMessagesBankFrom')
      drop index Messages.idxMessagesBankFrom 
if exists (select 'x' from sysindexes where name = 'idxMessagesTo')
      drop index Messages.idxMessagesTo -- ERROR HERE !! 
if exists (select 'x' from sysindexes where name = 'idxMessagesFrom')
      drop index Messages.idxMessagesFrom 
if exists (select 'x' from sysindexes where name = 'idxMessagesEnv')
      drop index Messages.idxMessagesEnv print 'Indexes Dropped'