too many nested evaluations (infinite loop?)

Hi,
for starters, sorry - long post - but does the following trigger anything with someone that suggests what I should be looking for in my script?
this is running on ubuntu, tcl version 8.6.14.
I have a somewhat complicated script that its scanning lines from my webserver access logs to find bad actors and block them. The main process is a long if then else chain of regexp looking for known attack patterns. The script shuts itself down once a day after midnight, and is restarted by a cron job at 12.15am.
Up to a certain point, it would run without this problem, and now it's coming up at least once a day.
After running for some time it keeps throwing "too many nested evaluations (infinite loop?)" errors- and the places it throws the error from changes.
the script is event based. This is open log file proc
proc openAccessLog {} {
   log "[now] Opening log file"
   set ::accessLog [open "|tail -f -n 30 /var/log/apache2/access.log" r]
   fconfigure $::accessLog -blocking 0 -buffering line
   fileevent $::accessLog readable [list checkForError $::accessLog]
   #initial run after 2 minutes
   after 120000 clearExpired
}
it also runs a couple of event procs like this one
proc stopper {} {
   set stop_file "/var/tmp/http.stop"
   if {[file exists $stop_file]} {
     log "[now] closing"
     file delete $stop_file
     saveSeen
     set ::stop "stop"
   } else {
     #log "." false
   }
   after 61000 stopper
}
and FYI,
proc now {} {
   clock format [clock seconds] -format {%e/%m/%y %T}
}
a recent error is in this proc:
too many nested evaluations (infinite loop?)
     while executing
"ParseFormatArgs {*}$args"
     (procedure "::tcl::clock::format" line 6)
     invoked from within
"clock format [clock seconds] -format {%e/%m/%y %T}"
     (procedure "now" line 2)
     invoked from within
"now"
     (procedure "stopper" line 4)
     invoked from within
"stopper"
     ("after" script)
Also note this script is using ::http::geturl to talk to external APIs, ("https://api.abuseipdb.com/api/v2/check")
and i THINK, this is where the problem starts. From the most recent crash, the first error was ...
too many nested evaluations (infinite loop?)
     while executing
"variable $token"
     (procedure "Finish" line 10)
     invoked from within
"Finish $token $msg"
     (procedure "::http::Connected" line 231)
     invoked from within
"::http::Connected $token $proto $phost $srvurl"
     (procedure "http::Connect" line 28)
     invoked from within
"http::Connect ::http::250 https {} /api/v2/check?ipAddress=172.192.10.125&maxAgeInDays=30"
thanks
Jonathan.