If all others fails => read the Datasheet carefully.
The SW_Tx_UART supports PSoC 3, PSoC 4 and PSoC 5LP.
Small notice on the page 7 of the SW_Tx_UART Version 1.10 Datasheet
.... is IMPORTANT ....
"Software Transmit UART component requires to have Instruction Cache to be enabled for PSoC 3 and PSoC 5LP. This could be done in PSoC Creator project Design-Wide Resources editor on the System tab. By default, this option is enabled".
If the Instruction Cache is disabled the SW_Tx_UART works but erroneously.
Behaviour - using 115200 Baudrate and 24MHz BusClock same number of characters transmitted, but all characters NONREPRODUCIBLE - RANDOMLY substituted.
NO WARNING in PSoC Creator 3.0 compilation/linking, NO USABLE INFORMATION from the logic analyzer.
May be this helps.