Z3 sort mismatch error about mythril HOT 2 CLOSED

(mythril) Cerebral-Cortex:IICOLib bernhardmueller$ cd truffle/
(mythril) Cerebral-Cortex:truffle bernhardmueller$ myth --truffle
Analysis result for CrowdsaleLib:
==== CALL with gas to dynamic address ====
Type: Warning
Contract: CrowdsaleLib
Function name: _function_0x3617dbba
PC address: 1237
The function _function_0x3617dbba contains a function call to an address provided as a function argument. The available gas is forwarded to the called contract. Make sure that the logic of the calling contract is not adversely affected if the called contract misbehaves (e.g. reentrancy).
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Affected code:

self.token.balanceOf(this)
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$  pip install mythril==0.10.11