I found a bug.
It replaces my client's gui and lags my client up every time I start Blockland. And even when I switch back to the default gui, it has leftover pieces from the gui I just switched to in my client.
Please fix this bug.
If it really bothers you, you could either lower the setting so it lags less by go to GUI Replacers Options and set the Sleep value to something higher. Try 10 for example. It will take a longer time to replace, but it should reduce the lag a bit.
If you don't want it to replace any gui at all in the beginning you could uncheck the Boot Replace. You could also uncheck other options like profiles if you find it not replacing it correctly. However, this will disable some guis like windows, checks, radios etc...
Also, if you already had a different gui when you added this mod, that means it will have that gui as default one.