division by zero error but im not dividing anything

Hi guys as the title suggests i keep getting the division by zero error but im not dividing anything. can anyone see an issue with the attached? i scratching my head. the code at the bottom is a custom indicator is this causing the issue?

// Definition of code parameters
DEFPARAM CumulateOrders = true // Cumulating positions deactivated
// The system will cancel all pending orders and close all positions at 0:00. No new ones will be allowed until after the "FLATBEFORE" time.
DEFPARAM FLATBEFORE = 100000
// Cancel all pending orders and close all positions at the "FLATAFTER" time
DEFPARAM FLATAFTER = 060000

// Prevents the system from placing new orders on specified days of the week
daysForbiddenEntry = OpenDayOfWeek = 6 OR OpenDayOfWeek = 0

if not onmarket then
c1 =1
c5 = 1
endif
// Conditions to enter long positions
indicator1 = CALL "trend/no trend"
c1 = indicator1

indicator2 = RSI[1](close)
c2 = (indicator2 < 30)
indicator3 = MACDline[12,26,9](close)
indicator4 = ExponentialAverage[9](MACDline[12,26,9](close))
c3 = (indicator3 CROSSES OVER indicator4)


IF (c1=0 AND c2 AND c3) and not daysForbiddenEntry THEN
BUY 1 CONTRACT AT MARKET
ENDIF

// Conditions to exit long positions
indicator5 = MACDline[12,26,9](close)
indicator6 = ExponentialAverage[9](MACDline[12,26,9](close))
c4 = (indicator5 CROSSES UNDER indicator6)
indicator13 = CALL "trend/no trend"
c9 = (indicator13 = 1)

IF c4 and c9 THEN
SELL AT MARKET
ENDIF

// Conditions to enter short positions
indicator7 = CALL "trend/no trend"
c5 = indicator7
indicator8 = RSI[1](close)
c6 = (indicator8 >= 60)
indicator9 = MACDline[12,26,9](close)
indicator10 = ExponentialAverage[9](MACDline[12,26,9](close))
c7 = (indicator9 CROSSES UNDER indicator10)

IF (c5 AND c6 AND c7) AND not daysForbiddenEntry THEN
SELLSHORT 1 CONTRACT AT MARKET
ENDIF

// Conditions to exit short positions
indicator11 = MACDline[12,26,9](close)
indicator12 = ExponentialAverage[9](MACDline[12,26,9](close))
c8 = (indicator11 CROSSES OVER indicator12)
indicator14 = CALL "trend/no trend"
c10 = (indicator14 = 1)

IF c8 and c10 THEN
EXITSHORT AT MARKET
ENDIF

// Stops and targets
SET TARGET PPROFIT 15
SET STOP pLOSS 10



//-------------------------------------------------------------------------
// Function : trend/no trend
//-------------------------------------------------------------------------
// period da ottimizzare
AA = 50
t=(LinearRegressionSlope[AA](close)-0)*SQRT(AA-2)/(STE[AA](close)/STD[AA](Barindex))
if t>1.96 then
beta=1
endif

if t<-1.96 then
beta=-1
endif

if t-1.96 then
beta=0
endif

return beta