Just installed EE3 massive errors....

Just installed EE3 and I’m getting this when trying to save a file in the template manager.

Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Severity: E_WARNING Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 hide details Severity: E_WARNING Warning file_put_contents(): Filename cannot be empty ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 74 show details Severity: E_WARNING Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Severity: E_WARNING Warning file_put_contents(): Filename cannot be empty ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 74 show details Severity: E_WARNING Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Severity: E_WARNING Warning Cannot modify header information - headers already sent by (output started at /var/www/html/EE3/system/ee/legacy/core/Exceptions.php:112) ee/legacy/core/Input.php, line 249 show details Severity: E_WARNING Warning Cannot modify header information - headers already sent by (output started at /var/www/html/EE3/system/ee/legacy/core/Exceptions.php:112) ee/legacy/libraries/Functions.php, line 437 show details Severity: E_WARNING

When I try to open the template manager I get the following:

Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Warning file_put_contents(): Filename cannot be empty ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 74 show details Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Warning file_put_contents(): Filename cannot be empty ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 74 show details Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Warning file_put_contents(): Filename cannot be empty ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 74 show details Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Warning mkdir(): Invalid path ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 87 show details Warning file_put_contents(): Filename cannot be empty ee/EllisLab/ExpressionEngine/Library/Filesystem/Filesystem.php, line 74 show details Warning Cannot modify header information - headers already sent by (output started at /var/www/html/EE3/system/ee/legacy/core/Exceptions.php:112) ee/EllisLab/ExpressionEngine/Boot/boot.common.php, line 463 show details